Thesis Arithmetic Concepts for Daily Life The research carried out in this thesis tries to understand how children learn some aspects of graphic representations in elementary mathematics and how they face the challenges that these present. This will be a pending task to be carried out, but for now, I prefer to consider this work as a continuity of said research, now venturing into the writing and conceptualization of elementary mathematics. with whom I have undertaken the task of venturing into issues and theories that have been quite a challenge but at the same time a great satisfaction. The influence of the work carried out by the members of this line of research and mainly by its founder, Dr. Jorge Vaca, has been so important that it is very difficult to determine which has been the purely original part from which this work is carried out. research and also to identify the main differences and continuities with which the consolidation of this branch in the line of research begins as a natural part. It is important to express that this thesis is the result of a collective work in which the members of the Written Language and Basic Mathematics Research Seminar participated, as well as the members of the tutoring committee and all the people who somehow intervened so that this thesis could perform and be defended. For this reason I will use the plural in the writing of this thesis, although that does not mean also sharing the responsibility of what is written in this way. To all the members and collaborators of the Written Language Research Seminar and In particular my most sincere thanks: THANKS Machine Translated by Google To Dr. Gérard Vergnaud, who received me at the Paris 8 University for an academic stay with him. For me it was a great experience for three reasons: the first is that I had the opportunity to present my thesis to him and get his opinion, he made suggestions and he positively assessed my work; This is very significant to me because he is the author of the theory on which I base this research. The second reason is because he chose from among his facsimiles of his publications those that he considered could help me on the subject raised and he gave them to me, a detail that I value very much. The third reason is because, being an academic who has contributed to the development of cognitive sciences and specific didactics, particularly that of mathematics didactics in France and whose reference is practically obligatory, he had the attention to listen to me, guide me and make efforts. for establishing a pleasant and clear communication and with a respectful and friendly treatment, his simplicity and humility are for me an example that great theorists and scientists are also simple people who love their work and like to share what they know with people who They show interest in their work. 6 comments and suggestions to improve it. In a special way I thank Verónica Aguilar, for her support in the revision of the text in Spanish and translations from French and English; Francisco Martínez for his support in field work and data preparation; Aracely Hernández for her contributions to this work; Amanda Cano and Denise Hernández for their suggestions; to Noel Xilot for his support in revising the text, to Edgardo Domitilo and Eréndira Espinoza for their comments and Francia Gutiérrez and Luis Gadea who at the time were members of the research line and the seminar. 1 To the directors and teachers of the schools who must remain anonymous but who allowed me access to their workspaces and mainly to the students who kindly gave me the opportunity to learn how they solve a mathematical problem with the additional effort to feel watched, and possibly evaluated, while doing it. Thanks to them this thesis was possible. To the colleagues who, at the time as officials of the Universidad Veracruzana, supported me from their trenches to carry out the activities of the doctoral program: to Dr. Ragueb Chain, who has supported not only my career in this postgraduate program but has also been pending the good development Machine Translated by Google Thank you all. • Dr. Mario Miguel Ojeda 7 To Lic. Alan Pérez for his support in computing matters. • Dr. Alejandro Gómez To Dr. Alicia Ávila as editor of the Educación Matemática magazine for her support and understanding, mainly regarding the bureaucratic aspects of this program. • Dr. Gustavo Martínez Sierra To the Mtra. Martha Romero for her support in managing access to the schools where the field work was carried out and for her comments on the thesis. of this thesis and of my academic life; to Dr. Miguel Casillas who, as director of the Humanities Area, supported me to carry out a stay in France; to Dr. Mario Miguel Ojeda who, as general director of the Postgraduate Studies Unit, contributed so that he could reach the end of this project and to Mtro. Juan Carlos Ortega, PhD fellow and colleague who gave me his support in difficult moments. To the Master Héctor Merino and Lic. Cynthia Palomino for their support from the CPUe magazine editorial. • Dr. Abraham Cuesta • Dr. Rosa del Carmen Flores To Lic. Guadalupe Zárate for her support in the administrative procedures. To the Master Francisco Sánchez for his support to access one of the secondary schools. To the readers of this thesis and members of the jury whose contributions and criticism allowed us to improve this thesis, in alphabetical order: Machine Translated by Google 8 Chapter IV reports the results of the first phase of empirical exploration, which constituted the inputs for the publication of a research article (curricular requirement of the doctoral program, Bustamante and Vaca, 2014)1 and in Chapter V we perform the microgenetic analysis . of a case that was the basis for the preparation of the second required article (Bustamante and Flores, in press). The didactics of mathematics, in the context of Mexican basic education, has been oriented mainly towards teaching itself, through the design and application of increasingly refined didactic situations on the different mathematical contents. We believe that this didactics could be complemented with the type of work that we propose, more focused on the psychology of learning. Our results show the need to make explicit the ideas that students build about mathematical content, about their symbolic representations and about their procedures that could be useful to improve the design and development of situations. Chapter II presents the theoretical references that frame the research, namely: the theory of conceptual fields, the operational theory of representation and the approach to situated microgenesis. Although we recognize that there are multiple research paradigms in the field of educational mathematics, we limit ourselves to this conceptual framework. Chapter VI analyzes 30 clinical interviews conducted with a 2 selected group of students who participated in the previous phase. In Chapter I the research work is introduced, the problem statement, the justification and its background are exposed. Of these, the works of the Written Language and Basic Mathematics line stand out : acquisitions, practices and uses, a research group from the Universidad Veracruzana that in recent years has explored the psychological, sociological and anthropological aspects of the acquisition and use of both written language as well as mathematics, in basic education students. This thesis seeks to understand in greater depth the role played by the various representations mobilized by students to solve a mathematical problem. Finally, in this chapter we review the curriculum by competencies in basic education and the didactic approach that locates problem solving as the axis for the teaching of mathematics and as a tool for evaluation and research in educational mathematics. In Chapter III we present the methodological tools with which the empirical work was carried out: the experimental design, the clinical interview and the microgenetic analysis. We describe the empirical referent and the phases and characteristics of data collection. SUMMARY 1 For the format of the references we have adhered, as far as possible, to the suggestions of The APA Publications Manual, 2010, 3rd edition in Spanish. Machine Translated by Google The work also made it possible to identify the need for students to differentiate representation systems and reconstruct their own rules and conventions in order to be able to use them properly. Only in this way can they assume the function of tools capable of supporting reasoning, promoting reflection and helping to maintain control of the activity during the resolution process, at the same time that they support working memory and, finally, enable adequate communication. of the procedures used and the results obtained. Without this clear differentiation and subsequent correspondence, instead of working as useful tools for solutions, the diversity of representations becomes a source of confusion that hinders or hinders said solutions. The results obtained in this research indicate that language and writing allow students to make explicit theorems and concepts-in-act, put them to the test and eventually be able to direct their modification towards more conventional forms. 9 In the last section we present the conclusions and final reflections. Furthermore, the translation, made by the thesis student, of the last publication that we know of on the theory of conceptual fields proposed by Gérard Vergnaud, is also included as an annex, to contribute to its dissemination. Machine Translated by Google In Chapter VI we analyze 30 clinical interviews with a selected group of students who participated in the previous phase. Teaching mathematics, in the context of the Mexican basic education, has been primarily oriented toward teaching itself, through the design and implementation of increasingly refined teaching situations on different mathematical contents. We sustain that this approach could be enriched by the kind of work we propose here, more focused on the psychology of learning. Our results show the need for specialists to become aware of the ideas that students build on the mathematical content, their symbolic representations and procedures, because that could be useful to design and improve mathematical situations. In Chapter II we expose the theoretical 3 framework of the research: the theory of conceptual fields, the operational representation theory (La théorie opératoire de la répresentation) and the situated microgenesis approach. Although we recognize that there are multiple research paradigms in the field of mathematical education, we limit ourselves to that conceptual frame. 10 In Chapter I the research is introduced and the problem statement is expressed as well as the justification and background. It highlights the work of the program research Written Language and Basic Mathematics: acquisitions, practices and usages, from which this work derives. In recent years, this research group of the Universidad Veracruzana has explored psychological, sociological and anthropological features of the acquisition and use of written language and mathematics in the basic education. This thesis seeks to understand in depth the role of the representations mobilized by students to solve a problem. Finally, in this chapter the competency-based curriculum in basic education is reviewed, as well as problem solving as a hub for the teaching of mathematics and as a tool for evaluation and research. In Chapter III we present the research design and methodological tools, which the empirical work was performed with: the experimental design, clinical interview and microgenetic analysis. We describe the empirical referent and the stages and characteristics of the data collection. Chapter IV reports the results of the first phase of empirical exploration. These results were the inputs to the publication of a research article (curricular requirement of the doctoral program, Bustamante and Vaca, 2014). In Chapter V we make the microgenetic analysis of a case, which was also the basis for the development of the second article required (Bustamante and Flores, in press). ABSTRACT Machine Translated by Google In the last section we present the conclusions and final thoughts. Finally, we annex the PHD student’s translation of the last publication that we know about the Theory of Conceptual Fields written by Gérard Vergnaud, in order to divulgate it. Results obtained in this research indicate that language and writing help make explicit the concepts and theorems-in-action of the students, to test them and eventually orient their transformation toward more conventional forms. 11 The work also identified the need for students to differentiate the representation systems and rebuild their own rules and conventions, in order to use them properly. Only in this way those systems can assume the role of tools that support the reasoning, encourage reflection and help maintain control of the activity during the resolution process, while supporting working memory and finally make the proper communication of the procedures used and the results obtained. Without such clear differentiation and subsequent correspondences, instead of working as useful tools for solutions, the diversity of representations becomes a source of confusion that complicates and blocks those solutions. Machine Translated by Google CONTENT I.1.1 Readers and their contexts............................................ ....................................... twenty I.3.2.2 Troubleshooting, a means of evaluating competencies.................................. 39 I. CHAPTER I. Introduction............................................ ......................................... 19 58 III.2.1 Procedure ................................................ ................................................................ ....72 I.3.2 The competency-focused model ................................................ 4 ............................ 35 II.3.3 Theorems and concepts-in-act ....................................................... .................................... 54 III.1.5 Application of the instrument............................................ .................................... 69 II.3.1 The conceptual field of multiplicative structures.................................................. 49 I.3 Rationale............................................... ................................................................ ................. 29 III.1.3 Tools................................... ................................................ ....... 67 II.2 Mathematical notation .................................................. .................................................. 46 III.1.1 Problematic situation............................................ ...................................... 58 I.1.2 Main aspects observed in the students’ procedures.......... 25 CHAPTER III. Methodology .................................................. .......................................... I.1 Background ............................................................. .................................................................. ................ 20 CHAPTER II. Theoretical framework.................................................. ...................................... 42 III.3 The clinical method ................................................ ................................................................ ........ 73 I.3.2.1 Life skills.................................................. .................................... 36 II.3.4 Linguistic signifiers.................................................. ........................................... 56 III.2 Clinical interviews................................................... ................................................................ .....71 III.1.4 participants................................................... ................................................ ....... 68 I.3.1 Competences in the latest educational reforms................................................. ..33 II.3.2 Scheme ..................................................... .................................................................. ............. 53 III.1.2 Analysis of the problem ............................................ ...................................... 60 I.2 Research questions ..................................................... ......................................... 27 II.3 Theory of conceptual fields.................................................. .................................... 48 12 II.1 Operational theory of representation ……………………………………. ............................. 44 III.1 Methodological design ................................................... .................................................. .58 Machine Translated by Google IV.2.1 Results by response categories.................................................. ...................... 89 IV.1 General results................................................... ................................................................ ..82 V.1.2.3 Partial closing............................................ ................................................................ 139 VI.1.2.1 Writing with directionality of the alphabetic system.................................. 170 VI.1.4.2 Empirical feasibility ............................................ .................................... 178 V.1.2.1 First phase............................................ ................................................................ ... 110 SAW. 1.1.3 Autonomous verification.................................................. ............................ 169 VI.1.4 Result ........................................ ................................................................ ............. 176 V.1.1 Description of the case................................................ ................................................ 108 VI.1.1.1 Figure of the problem: proportional relationship .................................. ...... 155 VI.1 Results according to the identified themes................................................ ...................... 155 VI.1.2.4 Dividend greater than the divisor .................................. ....................... 172 VI.1.3.1 Autonomous assignment of units ................................................ ...................... 174 IV.3 Conclusions from the experimental phase results................................................. ......... 102 CHAPTER V. Results of the microgenetic analysis................................... ................... 106 IV.2 Difficulty analysis ................................................... ............................................ 89 V.2 Conclusions of the analysis................................................ ............................................ 5 150 VI 1.2.2 Calculator, orality/writing ........................................ ......................... 171 13 V.1.2.2 Second part of the interview............................................ ............................ 129 III.4 Situated microgenesis................................................. .................................................... 75 CHAPTER IV. Results of the experimental phase................................................... ............ 82 VI.1.2 Division algorithm.................................................. ....................................... 169 VI.1.4.1 Relationship between the symbolic plane and the concrete plane ............................. 176 V.1.2 Microanalysis............................................... ................................................... ..... 109 VI.1.1.2 Correct and autonomous resolution........................................... ...................... 168 VI.1.3 Units ............................................................. .................................................................. ............. 174 VI.1.3.2 Carrying the decimal fraction to the unit ..................................... ......... 174 V.1 Andrea’s case ................................................ ................................................................ ....... 107 CHAPTER VI. Results of the analysis of the clinical interviews.................................. 153 VI.1.1 Problematic .............................................. ................................................ .......... 155 VI.1.2.3 Mechanics of the algorithm .......................................... .................................... 172 Machine Translated by Google CONCLUSIONS ................................................ ................................................................ .......183 14 VI.2 Conclusions of the chapter............................................ ............................................ 181 References................................................. ................................................................ .................... 190 Annex 1. Translation of Gérard Vergnaud’s theory of conceptual fields. .... 201 Machine Translated by Google Table 8. Distribution based on the type of magnitudes................................................. ..88 15 INDEX OF TABLES Table 7. Distribution according to the versions with or without distractor ..................................... 87 Table 9. Distribution of results by categories..................................................... .......... 89 Table 16. Issues related to the category Result ................................................ ............. 176 Table 4. Distribution of the students clinically interviewed..................................... 154 Table 2. Results by sex................................................. ......................................... 82 Table 11. Classification of data from clinical interviews.................................................. 153 Table 1. Distribution of the ages of the students.................................................. ..........69 Table 10. Distribution of the Sub-categories of Category 6................................................... 98 Table 4. Distribution of the results by type of locality.................................................. 84 TABLE INDEX Table 13. Subclasses of Figure of the problem.................................................. ...................... 156 Table 3. Results by educational level.................................................. ............................. 83 Table 12. Topics related to the Problem category ........................................... ........ 155 Table 2. Distribution of students by gender and school.................................................. ..68 Table 6. Results according to the version of the problem............................................ .............. 86 Table 15. Issues related to the Units heading.................................................. .............. 174 Table 3. Distribution of groups and calculator availability ........................................... 70 Table 1. Secondary school curricular map............................................ .................................. 32 Table 5. Results depending on the calculator. .................................................. ....... 85 Table 6 14. Issues related to the Algorithm category of the division ............................. 169 Machine Translated by Google Image 30. Inverts only the numerals of the division but not the units. ................. 132 Image 3. Small steps (we had to provide him with an additional sheet, which is tied here, so that he could finish his drawing). .................................................. .. 25 Image 1. Elizabeth’s procedure. ............................................................................ 23 Image 10. Example of resolution of category 5. ....................................... ................. 97 Image 19. Division that Andrea considers to be wrong................................................ .......118 Image 28. Say 70 divided by 35 and write 35/70.................................... ............................ 127 Image 37. The first item of information stated is not always the dividend.................................. 143 Image 8. Example of resolution of category 4. ........................................... ..................94 Image 17. Andrea’s productions in the experimental phase. ....................................... 108 Image 26. 3500/70= 50 cm. ................................................................ ......................................... 124 Image 33. Awareness of the organization of data in the division..................... 134 Image 35. Division of 5 children between ten bars........................................... .................... 136 Image 6. Example of resolution classified in category 2................................................. .92 Image 15. Another example of resolution of Sub-category 6 d. .................................... 100 Image 13. Example of resolution of Subcategory 6 c................................................ .........99 Image 22. Sum of the components of a correspondence table. ...................... 120 Image 24. Obtains 50 or 500 as a quotient.................................. ......................... 122 Image 31. Difficulty in assigning units to the quotient. ......................................... 133 Image 4. Steps. Item released from the PISA 2003 test. Taken from INEE, 2013... 59 Image 2. Estimated result. .................................................. ....................................... 24 Image 11. Prototypical resolution of Sub-category 6 a..................................... ........ 98 Image 20. Complement the quotient with units of measurement. .................................... 119 Image 29. Conventional writing of the division. ................................................................ .......130 16 Image 9. Modification of the text of the problem due to an incorrect result..................... 96 INDEX OF IMAGES Image 18. Correspondence table................................................. ................................. 113 Image 27. Check 50*70= 3500..................................... ................................. 125 Image 36. Division of 20 marbles among 40 children.................................. ..................136 Image 7. Example of resolution located in category 3................................................. ......94 Image 16. Example of resolution of Sub-category 6 e.................................. ....... 101 Image 23. Division 3500 cm by 70................................................ ................................. 121 Image 25. Division 3500/70................................................ .................................................. 123 Image 32. Conventional reading of the division.................................................. ...................... 133 Image 34. Division of 3 chocolate bars between 2 children. ......................................... 135 Image 5. Problem A, Brandon aged 11 years 8 months (11.8) primary school A (urban), no calculator .......................... ................................................................ ......................................... 90 Image 12. Example of resolution of Sub-category 6 b.................................. .........99 7 Image 14. Example of resolution of Sub-category 6 d.................................. ....... 100 Image 21. Relationship between the algorithm and the correspondence table............................ 120 Machine Translated by Google Image 49. What is meant by a step........................................... ............................ 165 Image 43. Division carried out under the theorem-in-act, the meters are located in the dividend................................. .................................................. ......................................... 149 Image 48. Successive multiplications to find the quotient. ................................. 164 Image 50. The word average refers to measurement and size to an intensive quantity. Image 42. Iconic representation of 20 pesos among 10 children. .................................... 148 Image 45. From iconic representation to the rule of three.................................................. .......160 Image 51. Mathematical writing with alphabetic directionality.................................. 171 Image 44. Division carried out under the theorem-in-act: the first item of information is located in the dividend.................................. ................................................................ ..................................... 150 ................................................................................................................................. 167 Image 47. Representation of the relationships of the problem through a number line. Image 38. 20 minutes divided by 60 seconds is equal to 0.3 hour and this is equal to 3 min... 143 Image 53. Shows the approximate distance of one meter. ............................................ 179 Image 46. Yéssica’s response obtained from a process of deduction and mental calculation..................................... ................................................................ ............................................ 161 Image 52. Gesture to indicate the size of a step. ................................................................ ..177 Image 40. Graphic representation of three tenths of an hour. ......................................... 145 ......................................................................................................................................... 17 Image 41. If a tenth of an hour is 6 minutes then 3 tenths are 18..................... 146 Image 39. Adjust the ratio as required. ................................................................ ......... 143 163 Image 54. Shows the approximate distance of two meters. ......................................... 180 Machine Translated by Google 18 Figure 6. Diagram of relationships of the linear function............................................ ............... 65 Figure 1. Representation plans (taken from Vergnaud, in press). ............................ Four. Five Figure 3. Scheme for defining a step. Source: self made. ............... 62 Figure 7. Diagram of relationships operating on the coefficients of proportionality. . 66 Figure 2. Diagram of relationships corresponding to the problem of steps. ........................ 60 Figure 4. Diagram of vertical relationships, with scalar operators. ............................ 63 Figure 8. Scheme of relationships by scalars.................................................. ...................... 112 Figure 5. Scheme of horizontal relationships, with proportional function operators..... 64 INDEX OF FIGURES Machine Translated by Google 2 I. CHAPTER I. Introduction It is important to clarify that the term capacity is used here and in the rest of the document as the possibility that the subject has to build schemes based on the situations they face. There will be situations in which the subject may not have schemes to face them successfully, but that does not mean that they cannot develop or enrich them. Our interest is focused on the conceptualization processes that imply mathematical knowledge in the 8 process of construction, and that are indirectly observable through verbal expressions and graphic representations made during the process of solving a mathematical problem. We recognize the importance of research of a cognitive nature to understand where the obstacles are found during the resolution of problems and deepen the understanding of the conceptualization processes of the problems. For this reason, this research focuses its attention on the learning process, on the student more than on the teacher and their teaching, highlights the mechanisms by which students face a problematic situation, the way to mobilize their mathematical tools to solve the problem. problem, the difficulties they experience and the means by which these difficulties might be overcome. To do this, we proposed to carry out a study that would allow us to deepen our understanding of the resolution procedures of students in the sixth grade of primary school and third grade of secondary school. Through the clinical interview, we seek to infer the statements and concepts evoked during the resolution process that could interfere with reaching an expected result. We believe that the presence of mistaken ideas or incorrect procedures does not mean that students do not have the capacity2 to solve problems, but rather that in the resolution process when they are not mastered at a level necessary to function as tools to favor the resolution process, they could even complicate it. The solid construction of such knowledge requires various situations and in the long term, which will allow students the possibility of using them appropriately. mathematical knowledge. 19 Machine Translated by Google I.1.1 READERS AND THEIR CONTEXTS I.1 BACKGROUND In mathematics, some problematic situations were explored in order to identify variations in the resolution procedures, differences in the graphic representations used and in the application of mathematical knowledge depending on the educational levels and sociocultural contexts in which the students were. The purpose of the exploration was to know how students face one of the items applied in one of the PISA tests. If the results reflect a low score, then we were interested in knowing specifically where the obstacles that prevented students from adequately solving an item were located. 20 The object of study was built from a first approximation to the contexts in which students in the last grades of primary, secondary and high school from 4 locations in the state of Veracruz develop, through the research project Readers and their contexts . (Vaca et al., 2010) whose objective was to investigate the specific weight that the school, the family, the locality, the classes they receive and their own cognitive processes have in the learning of reading and mathematics. In the procedures for solving the problems, interesting aspects were observed that require a more in-depth study for their understanding: differences between the graphic representations of the same concept, variation in the levels of conceptualization of mathematical knowledge necessary for the resolution of the tasks. proposals and various positions shown by the students before the applied problems. Since these items are designed for students who are 15 years old on average, we required a problem that could be solved by students in sixth grade and third grade in secondary school. For this reason, we set ourselves the task of building one with the same theme as PISA but without 9 the algebra requirements, a content that is not worked on by primary school students. Machine Translated by Google Version A was discarded because we wanted to observe what students were doing with data that required filtering (”by the minute”) and operate on the relevant data. your steps? Hector walks 35 meters taking 70 steps per minute. What is the size of each of his steps? We wondered who would take it into account, who would not, what obstacles Hector takes 70 steps per minute and advances 35 meters. What is the size of each of his steps? The second version (B) was also discarded because we consider that it presents two pieces of information (the speed in steps per minute and the distance traveled) that can be interpreted as independent of the unknown: the size of each one of the steps. Hector walks 35 steps taking 70 steps per minute. What is the size of would represent. c) The research had a phase where the instruments were tested through a pilot study. Three problem proposals with some variations in wording were made and tested: 21 b) At the time, it was considered that the chosen version allowed the ”additional data” to be maintained and by including the word ”giving”, the decoupling of the data with the unknown was resolved. However, after collecting the data and obtaining and Hector walks 35 meters taking 70 steps, what is the size of each one? Based on the data collected from the pilot study, version ”C” of the problem was chosen as one of the instruments to apply it to all the research subjects (110): of his steps? a) Synthesis of the research results Readers and their contexts concerning the resolution of the mathematical problem Machine Translated by Google Notwithstanding the foregoing, the results obtained with this ”defective” problem and with interviews carried out by several participants, some without experience in clinical interviews (students who mainly did social service), important veins were found to deepen, now more clearly and clearly. controlled by a single interviewer, the thesis student. The step problem mentioned above was applied to the entire sample (110 students). Although an important part of the interest of the authors was to know the procedures, analyzes were also carried out based on the results they arrived at. Only a quarter (24.5%) solved it correctly and autonomously (without the interviewer’s support), including those who argued that it could not be solved; 46.4% managed to reach a satisfactory answer, but with some intervention from the interviewer, while 29.1% could not solve it yet and with the support of the interviewer. Let us remember that this problem was applied to the last grades of the three educational levels: primary, secondary and high school. For example, Brenda, who studies the third grade of telesecundaria in a rural town, says orally that she divided 35 by 70, but in the graphical representation The approaches made were classified for analysis into 4 types: adequate (which include operations that can lead to the expected result as a rule of three and division with the correct data), division (but with data problems), other operations, and no written operations. Most of the students of the three educational levels opted for the division algorithm as the main resolution tool, but a large part of them also inverted the data in the written representation. Some interesting examples are described below (Vaca et al., 2010) where the aforementioned problematic situation was applied individually 10 and at the same time clinical interviews were conducted with each of the students. To share some results, we received comments from mathematics didactics specialists in which they expressed that the problem was not well written, that in those terms it was unsolvable because it required making at least two assumptions: that the distance is covered in one minute and that the average step size was sought. 22 Machine Translated by Google Would your step point five centimeters? [Five centimeter point? How much would five centimeter point be?] Five point... oh no, in millimeters that says [millimeters? and that would be how much, outlining it] for me they would be small, right? have been one foot on the other foot and so, right? [Aha, do you think that’s the case?] I say yes, I can’t find any other way. Another similar example (See Image 1) is given by Elizabeth, who was a telebaccalaureate student. The result you get is 0.5 and you doubt which unit of measurement you should use. which you do from left to right, first write 35 then draw the little house and then write 70 (as a dividend); For this reason, the data is inverted: 70/35 and therefore obtains a result of 2. It will be necessary to delve into this aspect during the clinical interviews to find out the characteristics of these interactions and what causes this type of response in both primary school students like middle school and high school. Here we can appreciate the convergence of the aspects already mentioned and that are interesting to explore in greater depth in this thesis: the variations between the symbolic systems, that is, between what is expressed verbally and what is effectively written, the reflections on their own written representations and its relationship with mathematical conceptualizations and graphic conventions. It first interprets the result as 0.5 centimeters and then as 0.5 millimeters, which also explains the feasibility of the result if you walk with one foot on top of the other foot. The following snippet shows how a result is misinterpreted by a problem reading its own writing, specifically the decimal point. 23 Image 1. Elizabeth’s procedure. Machine Translated by Google Unlike María José, Marcos does consider the data of the problem and also right of the 35, think for a moment and write in the quotient 5 then in another space multiply 70*5= 350, go back to the division and multiply the 5 by 70 and write in the remainder 00, add a point to the left side of the quotient ( .5) and asks:) Point five? Could it be .5 millimeters? On the other hand, we find students who use solution strategies that obey schemes activated by having represented the problem in a way that is divergent from the expected or non-canonical in terms of Flores (2003). makes a correct interpretation of it, expressed iconically (See Image 3). We have also found it with other students, who, when obtaining a decimal point in the quotient, consider that if the unit is fractional, the referent used must also be. If we are talking about meters, then it cannot be 0.5 meters but 0.5 centimeters or in this case 0.5 millimeters. 24 María José, for example (See Image 2), thinks about the size of her own step and makes an estimate of its measurement. It does not take into account the data of the problem and therefore does not carry out any arithmetic approach. It has been considered that when a problem goes beyond the students’ schemes, they can give up the problem or, as in this case, move away from conventional resolution procedures. [I tell you something? if what you want is to divide 11 the 35 meters by 70 steps, divide that distance by 70 then, 35 goes in and 70 goes outside if that’s what you want to do] (He laughs and writes 35/70, whispers and adds a point and a zero Image 2. Estimated result. Machine Translated by Google STUDENTS I.1.2 MAIN ASPECTS OBSERVED IN THE PROCEDURES OF THE Image 3. Small steps (we had to provide him with an additional sheet, which is tied here, so that he could finish his drawing). • Contradictions between representation systems (oral and written) 25 Marcos manages to graphically represent the problematic situation but fails to propose a mathematical calculation procedure to deal with the situation. He represents the action of walking through the drawings, taking care of the one-to-one correspondence between the jumps drawn and the number of steps mentioned in the text of the problem. Where he did not take care of that correspondence was in the line that represents the distance traveled. After completing his procedure, he concludes that Hector’s step size is “small”. Here we observe contrasts between the initial representation of the problem (figure in terms of Gréco and understanding scheme according to Flores, 2003), the drawing, and the applied resolution scheme. Choose a procedure that leads to intensive quantification. employed by the student. With the above, a series of resolution procedures have been shown that obey various schemes, examples of how the problem is assimilated to the students’ schemes and also represents a certain familiarity that motivates them to solve it. • Problems with the unit of mean in quotients less than one. The previous examples show some aspects that are addressed in this research: • Reflection on the feasibility of the result obtained. Machine Translated by Google relation to other writing systems Those who did, were able to solve the problem, even mentally. Due to the breadth of topics to be explored in the research ”Readers and their contexts” and the methodology used for these purposes, in addition to the participation of students who were doing their bachelor’s social service or who were studying their master’s degree, with little experience and lack training in clinical interviews, in said investigation we were not able to fully elucidate the reasons for the failures in resolution; In addition, at that time we did not have the necessary theoretical tools to be able to build the observables necessary to interpret the data collected. The realization of this thesis constituted the framework to deepen the understanding of the difficulties of solving this problem and to know in depth Vergnaud’s theory of conceptual fields, which seemed pertinent and coherent with our purpose. • Evidence of lack of practice of algorithms and multiplication tables, mainly in secondary and high school, perhaps due to the use of the calculator. • Mathematical tools activated during the solution of the problem in • Arbitrary use of the decimal point. • Partial knowledge of the division algorithm. function of the initial scheme of the problem (figure). 26 • Difficulties with the graphical representation of the division algorithm and its • Difficulties in the analysis of the relationship between the quantities 35 and 70. • The non-canonical representation of the problem and iconic solution procedure with a result with intensive magnitudes such as ”grades” or ”small” despite being in a school context. Machine Translated by Google I.2 RESEARCH QUESTIONS students during the resolution of the 12 problematic situations raised? we explore others with less intensity. We mainly concentrate more on treating graphic representation and conceptualization of the structures involved in the • What are the knowledge underlying the symbolic representations of • What relationships do students establish between alphabetic writing, students during clinical interviews, we delve into some topics and To do this, we aim to explore the characteristics of the relationship between oral language, multiplicative by primary and secondary students from rural contexts and • How does the use of the calculator influence the resolution of written algorithms, 27 resolution of a problem (with four variants) of the conceptual field of structures of the division algorithm and oral language? • How are the relationships between symbolization and conceptualization characterized? • What are the conceptual implications of the distinction between 35/70 and 70/35 per urban. In addition to some specific questions derived from this formulation: particularly with the division this small group of problems? of mathematical problems that cause low scores in the results of the concept of multiplicative structures? Notwithstanding the foregoing and as the investigation progressed, when working with the evaluations, what specifically these difficulties consist of. Initially we ask ourselves if the students experience difficulties in solving in the procedures for solving a problem belonging to the field part of the students? Machine Translated by Google outsourcing, but we agree with the statement that mathematical knowledge 28 own rules. concepts, to their reorganization, to reflect on them, to the awareness and It is built through action and not through language. Piaget would say: it is necessary but In addition to the previous questions, the availability of a calculator will be included as a variable in this investigation. As already documented, in the PISA test applications even officials give free calculators to students in the hope that they will improve their results. Likewise, in the Plan and study programs of basic education it is suggested the incorporation of the new The latter has not been differentiated from other writing systems and its We conceive that the domain of the mathematical representation system is It is important to underline, even if it is obvious, that oral language is a system Therefore, the objective of this study is to try to understand in greater detail the difficulties faced by basic education students when facing a mathematical problem: the relationship of these difficulties with the representation systems and with the level of conceptualization of the notions. involved in the problem. not enough. so to master this representation system it is also important to have to understand the relationship between systems of representation and conceptualization When the student says ”I am going to divide 35 by 70” he is speaking and is expressing a closely linked to the level of construction of the mathematical concepts represented of representation and that its adjustment or correspondence with other systems is substantial. The hypothesis under which this work is carried out is that the characteristics of the system has writing in the process of conceptualization; helps to identify the correspondence between systems. writing graph interfere with those of the mathematical notation system when it mathematics. consolidated the corresponding meanings. However, we recognize the role that relationship; 13 when he writes it, he sometimes reverses the relationship, which shows the lack of Machine Translated by Google We consider that some difficulties that students experience are related to the way in which they interact the different representation systems involved in the resolution process, specifically alphabetic writing, oral language, mathematical notation, in addition to those linked to the level of conceptual development, which they have achieved, of the mathematical notions involved. 29 technologies in the learning processes, including calculators, but in the application of tests such as ENLACE they are prohibited (Vaca et al., 2010, pp. 93 and 946). Due to such actions, we wanted to explore more systematically if the use of the calculator is truly a support for more students to give a correct answer to the proposed problem. Low scores have been reported in the results of standardized tests that purport to assess the competencies of Mexican students in mathematics, even in the national press (Avilés, September 8, 2009). For example, the Ministry of Public Education (2013) reports that the national average in the 2009 PISA test is 419 points compared to the Organization for Economic Development Cooperation (OECD) average of 501 points. Due to this, the interest arose, on the part of the applicant, to carry out a doctoral thesis that would allow knowing in detail what happens when students, between 11 and 15 years old, face a problem in the conceptual field of multiplicative structures. If they fail in their responses, be able to specifically observe and describe what they are failing at, and to the extent possible be able to understand and explain those failures. This study has as its main background the research Readers and their contexts (Vaca, Bustamante, Gutiérrez, Tiburcio, 2010) in which the sociocultural conditions of basic education students in some locations in the state of Veracruz are analyzed to search for relationships between their family, school and cultural contexts, and the way they deal with situations of written language and mathematics. In this last case, the authors identified that some of the difficulties experienced by students could be related to the linking of the different symbolic systems that intervene in the resolution processes, as well as with the I.3 JUSTIFICATION Machine Translated by Google (PRONAP), now the General Directorate of Continuous Training of Teachers in Service. Therefore, we set out to explore the relationships between the different forms of symbolization that students use while solving an arithmetic problem and the mathematical concepts that they mobilize during its resolution. We decided to consider the solution to a single problem, since our interest is to deepen the deductions and inferences that students make, as well as their calculations, and in particular relationships between different forms of symbolization without prioritizing the generality of knowledge in different mathematical situations. and in a complete conceptual field. Due to the fact that the incorporation of the so-called ”modern mathematics” in the educational systems in several countries did not have the expected results (Kline, 1988), in Mexico the 1993 reform was proposed, which incorporates the results of the constructivist investigations carried out in the which at first was called the DIECINVESTAV Psychomathematics Laboratory, in whose works I. Fuenlabrada and D. Block take up the contributions of the French school, mainly from the currents 30 If 14 we start from the idea that mathematics is a body of knowledge that can help people better deal with the various activities and contexts in which they operate, we would also have to recognize that most of us find it difficult to do a practical application of the mathematical knowledge learned during our school training (terminologies, concepts, formulas, operations, definitions, equivalences, etc.) in non-school problems. It seems that this difficulty is now minimized thanks to the technology with which we access computer and information programs that allow us to resolve the issues of daily life. constructivists of knowledge, mainly from Brousseau (Fuenlabrada, 2007; Fuenlabrada and Block 2009). The processes for incorporating new proposals are generally long-term. It has been mentioned that even after 10 years of said reform there were still indications that many teachers continued to work in a traditional way without accepting or fully learning about the new proposal, despite the efforts of the SEP and specifically the Undersecretariat. of Basic Education that launched the National Program for Permanent Updating of Basic Education Teachers in Service weak construction of some mathematical concepts. Machine Translated by Google Gérard Vergnaud (Brousseau, 1994) Brousseau has expressed the retos that the didactic of This approach has been developed in research in Mathematics Education as well as in curricular development projects, for more than two decades, in various parts of the world, these studies have been carried out from a constructivist conception of learning (p. 2) mathematics had to overcome, among which stand out: the training of teachers, necessary conditions for the student to interact with the learning objects and mobilize strategies for solving problems with their own resources, while the teacher’s job consisted, in principle, in guiding the student so that, based on spontaneous strategies and resources individuals, could build more conventional notions and knowledge through the prepared didactic situations. important efforts to improve teaching and learning trying to incorporate the results of research on learning and teaching mathematics, for example in Mexico from institutions such as the Department of Educational Research and the Department of Educational Mathematics, belonging to However, currently there is a new curricular reform, new textbooks and a curriculum now based on the development of competencies with the justification that previous reforms have not resolved the problems: school failure, lack of application of mathematical knowledge in real problems of daily life and currently the low results in the different evaluations both nationally and internationally. Of the latest curricular reforms, at least in 1993, to the Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN). Fuenlabrada and Block (2009) express it as follows: excessive criticism of the results of didactics, false ideas about the This is not exclusive to Mexico. In the Tribute made to Guy Brousseau and 31 The methodological approach proposed by the new Plan and programs for Basic Education published in 1993 locates, […], problems as the core of learning around which teaching is organized. The educational reform of 1993 guides teaching efforts to create the Machine Translated by Google Table 1. Secondary school curricular map. Note: Source: (SEP, 2006, p. 31). specialized both for the training of mathematicians and of didactic In 15 the basic education curriculum in Mexico (Secretaría de Educación Pública, 2009), mathematics has an important space along with Spanish and science. For example, for fourth, fifth and sixth grades of primary school, 200 hours are granted annually (although in practice this does not necessarily happen), which implies a considerable scheduled time for working with the selected contents. didactics He considered that they were on the right track to overcome them, creating institutions mathematics and teachers In secondary school, the time allocated to mathematics is the same as Spanish and science takes on greater importance, as can be seen in the number of hours assigned weekly in Table 1. 32 Machine Translated by Google I.3.1 COMPETENCES IN THE LATEST EDUCATIONAL REFORMS The reform initiated in preschool, both in terms of school management and the development of skills, is expressed as follows: The central purpose of the curricular reform of this educational level has been the transformation and improvement of pedagogical practices, guiding them to favor the development of competences in children; This implies changes in the conceptions that have predominated for a long time about young children, their development and learning processes and, consequently, The efforts made in terms of school work to promote the learning of mathematical tools have also been guided by the cultural requirements of each country. In Mexico, traditionally, both the learning of the language and that of mathematics have been valued, considering these as knowledge that the new generations must master in order to function adequately in the different areas in which they interact. The global changes in economic and political matters in the world oriented the curricular design of education, in Mexico and in many countries, particularly in basic education, to the development of ”competencies” that we consider is a notion that is not clearly defined and that therefore, it provokes divergent interpretations both theoretically and practically (Vaca, Aguilar, Gutiérrez, Cano, and Bustamante, in press). In this way, the Mexican educational system begins its transition to this new objective, which is initially specified in preschool. The curricular reform of preschool education aims to contribute to the transformation and improvement of pedagogical practices and the conceptions that support them (beliefs about how young children are and learn and what is the function of preschool education), so that so that the little ones develop the cognitive and socio-affective skills that are the basis for lifelong learning. (Secretary of Public Education, 2009, p. 27) 33 Machine Translated by Google This reform of basic education puts the term of competences as a central axis: At the end of the period of generalization of the reform in secondary school, the The main strategy for achieving this objective in basic education proposes carrying out a comprehensive reform of basic education, in which the notion of competencies is resumed, which allows addressing the challenges facing the country in the face of the new century, and helped to achieve greater articulation and better efficiency between preschool, primary and secondary. (Education secretary (Secretary of Public Education, 2009, p. 27) Integral Reform of Secondary Education (RIES) and which had several phases as a training process, of which the last one was carried out in the 2008-2008 school year. reform in primary education that has its first phase 16 in the year 2009. In 2006 it was the turn of the secondary school, through what was called 2009: 34 The primary challenges are focused on raising quality and incorporating into the curriculum and daily activities: the renewal of learning content and new teaching strategies, the intercultural approach, the use of information and communication technologies as support. for teaching and learning; learning a mother tongue, be it an indigenous language or Spanish, and an additional language (indigenous, Spanish or English) as a subject of state order; the renewal of the Civic Education subject for Civic Education and Ethics, and the innovation of educational management. (Secretary of Public Education, 2009, p. 9) [...] in the 2008-2009 school year the generalization of the third grade was concluded, however its consolidation is still a pending task; Without this consolidation, the articulation of all basic education will not be possible. Difficulties arose in generalization due to the heterogeneity of the secondary level, not only because of its modalities (general, technical, telesecundaria), but also because of the operating conditions in the states (and within them, in the different regions) [Secretariat of Public Education, 2006, p. 29]. about what corresponds to the school to do to favor learning. Machine Translated by Google I.3.2 THE COMPETENCE-CENTRED MODEL We know that the term competition has its history and its own evolution (Vaca, J. et al., in press) and we agree with the observations made by Vergnaud in the interview given to Baudelot (2005) about this concept, who considers that it is not it is a scientific concept and it is not a self-sufficient concept; for him it is necessary to take into account the situations in which the subjects develop. He considers that competence is a value judgement, one is competent or one is not competent or one is more competent today than yesterday, or else, X is more competent than Y. The term competence has been used in the study programs at the higher levels and has now been adopted in basic education. It is necessary to make a brief analysis of the official documents that take up this concept. This model, which serves as the central axis in the reform of basic education, that is, from preschool to high school, can be analyzed from different perspectives. The document of the SEP, in the Plan and study programs for primary education expresses his: He mentions that for there to be value judgments like these, there must be criteria Educational research has sought to specify the term competencies, agreeing that these are closely linked to solid knowledge; since its realization implies the incorporation and mobilization of specific knowledge, so there are no skills without knowledge. 35 A competence implies knowing how to do (skills) with knowing (knowledge), as well as the assessment of the consequences of that doing (values and attitudes). In other words, the manifestation of a competence reveals the putting into practice of knowledge, skills, attitudes and values for the achievement of purposes in diverse contexts and situations, for this reason competence is conceived as the mobilization of knowledge (Perrenoud, 1999 ). Making basic education contribute to the formation of citizens with these characteristics implies considering the development of competencies as a central educational purpose. (2009, p. 40) Public, 2009, p. 9) Machine Translated by Google I.3.2.1 LIFE SKILLS 3. technological evolution (Vaca et al., 2010, p. 62). discharge: The 17 performance criterion: I am more competent today than yesterday because I can do things that I did not know how to do yesterday. The result of the activity is enough to say that X is more competent today than yesterday or that it is more competent than Y. Performance: X is more competent if it performs better, faster, more reliably, more compatible with the work of others in a group. However, you have to analyze the activity. The idea that there are ways of proceeding that are stronger, simpler than the others, cheaper, faster, more reliable is very important in the definition of competence. If we consider the criteria that Vergnaud proposes to make a value judgment that would correspond, therefore, to the assessment of competence, the complexity of the concept is observed when it is linked to the educational field, mainly in teaching based on this curricular organization and on the evaluation of the competences developed under the following profile. 36 1. Resources and their choice: X is more competent if he has resources that he can adjust to different problem situations and finds a way to cope with the task. It is seen there that it is not a scheme but a set of schemes and the competition would consist of choosing the best ones to mobilize in each problematic situation that arises. 2. The competencies that the SEP proposes are intended to contribute to the achievement of the profile of Protection in new situations: The person who is less helpless in a new situation is more competent. This criterion is very important today in the business world and is closely linked to the rapid evolution of society and the of which he distinguishes four: • Competences for permanent learning. They imply the possibility of learning, 4. Machine Translated by Google • Competences for information management. They are related to the search, • Skills for handling situations. They are those linked to the possibility of organizing and designing life projects, considering various aspects, such as historical, social, political, cultural, geographical, environmental, economic, academic and affective aspects, and having the initiative to carry them out, managing time , promote changes and face those that arise; make decisions and assume their consequences, face risk and uncertainty, propose and carry out procedures or alternatives for problem solving, and manage failure and disappointment. • Skills for life in society. They refer to the ability to decide and • Competencies for coexistence. They imply relating harmoniously with others and with nature; communicate effectively; teamwork; make agreements and negotiate with others; grow with others; harmoniously manage personal and emotional relationships; develop personal and social identity; Recognize and value the elements of ethnic, cultural and linguistic diversity that characterize our country, raising awareness and feeling part of it from recognizing the traditions of their community, their personal changes and the world. identification, evaluation, selection and systematization of information; thinking, reflecting, arguing and expressing critical judgments; analyze, synthesize, use and share information; knowledge and management of different logics of knowledge construction in various disciplines and in different cultural areas. assume and direct their own learning throughout life, to integrate into the written culture, as well as to mobilize the various cultural, linguistic, social, scientific and technological knowledge to understand reality. act critically in 18 the face of social and cultural values and norms; proceed in favor of democracy, freedom, peace, respect for legality and human rights; participate taking into account the social implications of the use of technology; participate, manage and develop activities that promote the development of localities, regions, the country and the world; act with respect towards sociocultural diversity; combat discrimination and racism, and manifest an awareness of belonging to their culture, their country and the world. (Secretary of Public Education, 2009, p. 43) 37 Machine Translated by Google h) Promotes and assumes care for health and the environment, as conditions that favor an active and healthy lifestyle. e) Knows and exercises human rights and values that favor democratic life, acts and fights for social responsibility and adherence to the law. i) Take advantage of the technological resources at your fingertips, as means to communicate, obtain information and build knowledge. basic manages to display the following features: b) Argue and reason when analyzing situations, identify problems, formulate questions, make judgments, propose solutions and make decisions. Values reasoning and evidence provided by others and may modify own views accordingly. f) Assume and practice interculturality as a wealth and form of coexistence in social, ethnic, cultural and linguistic diversity. a) Use oral and written language to communicate clearly and fluently and interact in different social and cultural contexts. In addition, they have the basic tools to communicate in an additional language. c) Search, select, analyze, evaluate and use information from various sources. 38 g) Know and value your characteristics and potential as a human being; knows how to work in a team; recognizes, respects and appreciates the diversity of abilities in others, and undertakes and strives to achieve personal or collective projects. d) Interpret and explain social, economic, financial, cultural and natural processes to make individual or collective decisions, based on the common good. During the formative process it is intended that the student at the end of the education Machine Translated by Google • Program for International Student Assessment (PISA). • Trends in International Mathematics and Science Study (TIMSS) These features, once concretized, closely resemble the purposes of the 1993 reform. 2º Acquire the fundamental knowledge to understand natural phenomena, particularly those related to the preservation of health, environmental protection and the rational use of natural resources, as well as those that provide an organized vision of history and the geography of Mexico. 1º Acquire and develop intellectual skills (reading and writing, oral expression, information search and selection, the application of mathematics to reality) that allow them to learn permanently and independently, as well as act with efficiency and initiative in the practical matters of everyday life. 3rd They are educated ethically through knowledge of their rights and duties and the practice of values in their personal lives, in their relationships with others and as members of the national community. • Tests for Educational Quality and Achievement (Excale). In the end, whether they are objectives, purposes, traits or competencies, the measurement of their achievement is carried out through ”standardized” tests whose main tool is the formulation of written problems. In Mexico, 4 tests have been applied mainly: 39 4th Develop attitudes conducive to the appreciation and enjoyment of the 19 arts and physical exercise and sports (Secretary of Public Education, 1993). j) Recognizes various manifestations of art, appreciates the aesthetic dimension and is capable of artistic expression. (Secretary of Public Education, 2009, p. 43) I.3.2.2 PROBLEM RESOLUTION, MEANS TO EVALUATE THE SKILLS Machine Translated by Google They confirm the heterogeneous nature of the ways of working and the universes of reference mobilized by the students evaluated by PISA, regarding the impossibility of reducing them to simple reading and written comprehension skills. These reinforce the hypothesis according to which the PISA tests, which their creators present as evaluators of this type of competence, evaluate more complex and heterogeneous processes than the former (p. 115). Bautier et al. (2010) carried out a study in France on the PISA tests and consider that the conclusions they reached: • National Assessment of Academic Achievement in School Centers (Link 3 ). 40 According to the INEE 2005 Pisa document for teachers, in general Mexico ranked 38 out of 43 in most of the mathematics reagents released by the OECD; in others, last place. If we take into account what mathematical competences imply from Vergnaud’s perspective, we wonder which of the criteria If we take into account the competency-based model and the assessment style of national and international tests, we note that problem solving continues to be the means to assess mathematical learning, although based on the results of the research Readers and their contexts (Vaca et al., 2010) and other reflections (Bautier, Crinon, Rayou & Rochex, 2010; Vaca, 2005) it is clear that the standardized assessment of students’ knowledge presents considerable methodological problems and therefore the results of the evaluations must be interpreted taking into account the sociocultural contexts of the students who participate; however, educational programs and policies were created based on those results and the results did not change substantially. The apparent elimination of the ENLACE test could mean that the rejection of all the actors directly involved in it has finally been recognized: teachers, students, parents and also researchers, as reported by the latest research exposed in national forums ( Perez, 2013; Ray, 2013). However, there is also the possibility that another form of evaluation with the same characteristics or with greater problems is promoted instead. 3 Proof that the current secretary of public education had announced that for this 2014 it will no longer be applied to evaluate the performance of students and teachers in the Mexican educational system. Machine Translated by Google For all these lines of discussion, we are interested in knowing in detail how What he proposes to make this value judgment coincides with those of the PISA test to place students in that position. It is clear that one thing is to give the answer to a problem and another is how the resolution procedure was. Two students can arrive at the same result but by different procedures: one more powerful and general and the other with detours, hesitating and spending more time on it. The above taking into account the second criterion proposed by Vergnaud, that of development. Our students face a math problem. 41 Machine Translated by Google CHAPTER II. Theoretical framework The current knowledge of the subject comes from the interaction between his It results mainly from the internalization process. The theoretical 20 referent that we have chosen to approach this problem is the operational theory of representation and the theory of conceptual fields by Vergnaud (1990, 2009), which we consider a contemporary constructivism that takes up the contributions of Piagetian theory, of the ”group of strategies” by Bärber Inhelder (Inhelder and Caprona, 2007) and the reflections of Pierre Gréco (1979-1980; Gilis, in press) on the subject’s cognitive functioning. This theory of Vergnaud also has important links with the theory of didactic situations by Brousseau (1997) and finally the studies of those of situated microgenesis, a psychological current that we consider to be the continuity of Piagetian constructivism proposed by Saada-Robert and Balslev (in press). . formulation of his theories: previous knowledge and experience. The main theoretical and epistemological influences that guide this work are from Gérard Vergnaud, who has taken up the main theses of Jean Piaget in the Knowledge is a process of adaptation, it derives from the adaptation of the However, because Piaget sought the explanation and description of knowledge and intelligence through logical structures and because these structures are not applied systematically to the same types of tasks or problems if, for example, the content is changed, what was called décalage (lag), is that a current of studies emerged that delve into the application of cognitive structures to specific situations, to this new current that we call contemporary constructivism. Instead of characterizing Piaget’s ”epistemic subject”, these investigations were oriented to investigate how the ”psychological subject” acts in a situation, that is, how an individual updates such logical structures or meaning structures in specific situations and in particular contexts. Are Knowledge comes fundamentally from action on the world. 42 individual to his environment. Symbolic activity is the internal counterpart of overt activity and Machine Translated by Google Rouchier (Artigue, Gras, Laborde y Tavignot, 1994) considers that both Vergnaud and He is part of a small pioneering group in the didactics of the disciplines and in 43 Vergnaud takes up Piaget’s interactionist thesis and delves into the interaction relationship between subject and object, he proposes that, if knowledge is adaptation, what adapts are the subject’s schemes to situations. Therefore, the Situation Schema pair is theoretically more productive than the subject-object pair. It is not just a terminological change, but it implies on the one hand not seeing isolated objects but situations and how they are faced not by the average, abstract subject, but by a flesh and blood subject in a determined and situated context (the pragmatics of the subject by Pierre Gréco). Therefore, the analysis of situations acquires a central role in the understanding of the cognitive development of the subject, a theory developed in depth by Guy Brousseau for the didactics of mathematics. He is director emeritus of research at the National Center for Scientific Research in France (CNRS for its acronym in French), has directed more than 80 doctoral theses, was a student of Piaget whose thesis on aesthetics he defended at the Sorbonne in 1968 before the Genevan teacher. the didactics of mathematics in France and Switzerland. But who is Vergnaud? Merri (2007), in the presentation of the work in Tribute to Vergnaud “Activité Humaine et conceptualisation. Questions à Gérard Vergnaud” mentions that his influence is not only related 21 to the best-known topics, namely his theory of the schema and of conceptual fields, but also to his lesser-known works such as the one on the notion of calculable representation published in 1975 whose Translation has been made in the anthology ”What the hell are the skills” (Vaca et al., in press). En la obra “Twenty years of mathematics education in France”, André Annick Weil-Barais in the preface to the same work (Merri, 2007) describes him as an incessant activist for the development of a psychology capable of responding to society’s problems, which include both access for all children to knowledge values of French culture (mathematics and science) as well as the development and transmission of professional experience. Research was carried out by Piaget’s collaborators and students: Bärber Inhelder, Pierre Gréco, Jaqueline Bideaud, Saada-Roberts and also by Gérard Vergnaud. Machine Translated by Google II.1 OPERATORY THEORY OF REPRESENTATION Given that he conceives that the representation is not unequivocal to reality, but that there is These computations are carried out on different representation planes, hence the second concept, ”calculable representation”. According to this author ”The notion of representation has returned to the forefront of psychologists’ concerns, after having been deliberately ignored by a large number of experimentalists for many years” (Vergnaud, in press, p. 179) and ” The notion of relational calculus helps to clarify and make explicit the too vague notion of reasoning. Brousseau are the ones who have contributed the most to the development of the didactics of mathematics. But Guy Brousseau has concentrated more on the definition, classification and description of situations (even more than is necessary according to Vergnaud) than on the structures of meanings or schemes of the subject. Two of the concepts that we will use to account for the observed processes and analyze the students’ responses is relational calculus and calculable representation, both proposed by Vergnaud (in press). The author states that there are two large categories of relational calculus: Vergnaud (in press) defines representations as hypothetical constructions that must be inferred from the subject’s observable behaviors. A great variety of hypotheses can be formulated about these representations, so it is only possible to operationalize this notion if the hypothetical representations are calculable, that is, they lend themselves to relational computation. 44 (Vergnaud, 2004, p. 28). 179). verified or accepted. • Deduce new relationships from established or accepted relationships (p. Deduce a behavior or a rule of conduct from relationships Machine Translated by Google Figure 1. Representation plans (taken from Vergnaud, in press). several representations and are of different levels, then he also considers the correspondences between the different planes of representation, which he calls homomorphisms (same structure). It means that in the representation of reality there must be a homomorphous structure that allows operations (of thought) to be carried out that will eventually lead to the solution of the problem, but on the level of reality. different planes of representation. However, a system cannot calculate on another system if there is no homomorphism of the represented system in the representative system. Who says homomorphism does not say isomorphism. In the realityrepresentation application, they are classes of aspects, relations and processes 22 that are represented to enter into the calculations, not singular phenomena (Vergnaud, 1991, p 15. The translation is ours). 45 The notion of homomorphism is crucial to understanding the relationships between Figure 1 outlines the relationships between different planes of representation. In mathematics didactics, Vergnaud considers that it is necessary to seek to understand what are the prior representations that students must have (or master) in order to better understand canonical representation systems. Machine Translated by Google II.2 MATHEMATICAL NOTATION precisions regarding mathematical notation. From the above, it is necessary to define some concepts that are important different. Therefore, it is important to make a small detour to make some 4. The representation is applied to states, events that are state diachronies, relationships or transformations that are classes of synchronies or diachronies, to classes of relationships or transformations that are already invariant (p. 189) The canonical representation that this author defines is socially consensual and Mathematical writing has played a very important role in the to understand the resolution process: conceptual field and scheme. In relation to writing, Harris (1999) proposes an integrational semiological theory, in which he also takes into account mathematical and musical notation that are practically not contemplated in the classifications that tried to form grammatology. history, evolution, which has rules and principles. As well as writing systems Finally Vergnaud (in press) reaches 4 conclusions: agreed. It is a cultural product and in mathematics it obeys a system with its own 46 2. This allows explaining how a subject solves the problems of reality but also how certain high-level representations are preceded by other weaker ones that it is important to analyze. specific representation that by its nature and function obey rules and principles 3. Morphisms between representations are at the center of cognitive activity. Undoubtedly, you have to look for the best representations, but it is also useful to put into play the correspondences between different representations. 1. The notion of representation is not univocal, in the sense that one can never speak of a single possible and useful representation. have their own characteristics, for mathematics systems have been developed Machine Translated by Google Harris (1999) mentions that the most decisive invention of antiquity was the According to Harris (1999, p. 187) ”the scriptural structure of mathematics is designed with the aim of integrating various types of calculations” and does not obey an attempt to match this notation with the language or with phonetic units, so He calls it non-glottal writing. In fact, Ferreiro clearly established that writing has never been intended to represent speech, but rather language. Hence its important distinction between transcription code and representation system (Ferreiro, 2006). It can be thought that a constituted system of representation is acquired by new users as if it were a code. Such is the underlying conviction in most of the pedagogical proposals related to the teaching of reading: the child is prepared to recognize the letter units by exercises to recognize the phonetic units and the units are related to each other. them (avoiding as much as possible the so-called ”exceptions” to the principle of bi-univocity between letters and phonemes). Epistemological questions are thus ignored 23 and, nevertheless, the greatest difficulties of children are of an epistemological nature, as the studies reported in this chapter show (Ferreiro 2006, para. 236). 47 In the case of writing mathematics, it is not a transcription code but a representation system. Therefore, the processes of acquisition of this system by students can face the same difficulties as with the alphabetic system, which have already been widely studied. What we have observed is that when students begin to understand the mathematical representation system, they mix the glottic of the alphabetic writing system with the writing of numbers, for example, since numerals are a logographic representation system, children use it morphographically. In the same way that they graphically represent a division respecting the directionality of alphabetic writing (from left to right) based on the linguistic expression of the division; as if each graphic mathematical element corresponded to a segment of the expression. Detailed analyzes of this will be made later. The construction of mathematics is a system of representation, which, like any system, is socially constructed and has evolved throughout history. Machine Translated by Google This theory, according to its author, has the purpose of describing and analyzing the progressive complexity of the mathematical competences that students develop inside and outside the school, and establishing the relationships between the operative form and the predicative form of knowledge. Consider that a conceptual field: [...] from a semiological perspective, this invention represents not an evolution, but a complete break with the notion that written signs must agree with or reflect the structures of oral language. In other words, that notation could not have been invented at all if integration with speech had been the inventor’s primary concern (p. 190) 48 It is at the same time a set of situations and a set of closely linked concepts. By this I mean that the meaning of a concept does not come from a single situation but from a variety of situations and that, reciprocally, a situation cannot be analyzed with a single concept, but rather with several, forming systems (Vergnaud, 2009). , p.86). Sumerian notation based on position and that marks a difference with glottal writing systems. In the case of division writing -which concerns us in the problem to be investigated-, its layout is related to the syntagmatic of mathematical writing that it calls tabular, referring to the tables of squares and square roots of Babylonian origin ”where two sets of factors jointly determine the significance of an interrelated series of discrete shapes” (Harris, 1999, p. 195). It is then a writing system with its own characteristics and logic, which favor calculations and support memory. It is a representation system that must be reconstructed by students in order to be understood and must be differentiated from other writing systems, especially alphabetic writing, which is the one that most frequently interacts both inside and outside the school. II.3 THEORY OF CONCEPTUAL FIELDS Machine Translated by Google In general terms, the main categories that Vergnaud (1994) personal, October 20, 2010) whose construction implies interaction with multiple situations with each one to find their invariances that strengthen their singularities but at the same time differentiate them from each other. In this way, any other concept necessarily implies the relationship with other concepts forming systems; that of 24 automobile, requires the link with other concepts, for example: transportation, engine, driver, speed, tires, etc. proposes for multiplicative structures: For elementary mathematics, Vergnaud (1990) proposes two conceptual fields from which mathematical problems can be classified: that of additive structures and that of multiplicative structures. The first defines it as the set of situations that require an addition, a subtraction or a combination of said operations. The conceptual field of multiplicative structures defines it as the set of situations that require a multiplication or a division or a combination of such operations. For the purposes of this work, the four main types of problems of multiplicative structures will be described (Vergnaud, 1990). Vergnaud (1990, p.197) defines it as the set of situations whose treatment involves one or several multiplications or divisions, and the set of concepts and theorems that allow analyzing these situations: simple proportion and multiple proportion, linear and non- linear, direct and inverse scalar ratio, quotient and product of dimensions, linear combination and linear application, fraction ratio, rational number, multiple and divisor, etc. 49 From the situational point of view, Vergnaud (1994, p. 46), the conceptual field of multiplicative structures comprises a large number of situations that need to be carefully classified and analyzed, in such a way that the competencies developed by the students can be hierarchically described. students inside and outside of school. For example, the concept of ”son” cannot be fully understood without the concepts of mother, father, family, etc. (Dr. Rosa del Carmen Flores, communication II.3.1 THE CONCEPTUAL FIELD OF MULTIPLICATIVE STRUCTURES Machine Translated by Google • • • • • He proposes four classes of elementary problems: For this, he mentions that the key point is to consider the action of the subject in the situation and the organization of his conduct. It states that there are two types of situations: the first is when the subject has the cognitive tools to face the situation or problem and in these cases automatically applies a scheme. The second type is when the subject does not have the ”skills” and needs to reflect, search and try, try various schemes, thus favoring discovery. He also mentions that the analysis of multiplicative structures is completely different from the analysis of additive structures, since the base relations are not ternary but quaternary. He states that the simplest multiplication and division problems involve the simple ratio of two or more variables, one in relation to the other (Vergnaud, 1994, p.153). • The division-partition. Simple proportion. He proposes (didactically) a graphic representation system to show the relationships between the magnitudes of the data of the problems that favors its analysis (Vergnaud, in press). Use rectangles for states and roundels for transformations or relationships. The multiplication. Vergnaud mentions that in multiplicative structures, unlike additive ones, ”the simplest base relations are not ternary but quaternary, because the simplest multiplication and division problems involve the simple ratio of two variables in relation to each other.” ” (1990, p. 170 and 2001, p. 214) Comparison between ratios and proportions. The fourth proportional. • Concatenation of simple proportions. The division-quotation (or grouping). 50 Machine Translated by Google 51 Without this scheme, someone could say, first let’s determine how many marbles he won or lost in total, if he first lost 25 13 and then he won 7 then he lost 6 in total. proposes to use the scheme of Figure 2: (Vergnaud, in press, p. 181). But what is the nature of these numbers? The representation shown above helps to understand that 13 and 7 are transformations and we can also do operations with them and not only with the states. For example, from the composition of both transformations, we obtain -6, which represents the total number of marbles that Pedro lost. If it is known that applying this transformation to the initial state (unknown of the problem) the final state is obtained, then if the reciprocal of said transformation is applied to the final state (45) it is possible to calculate the initial state: that is, 51 marbles. In Figure 3 “Pedro has just played two games of marbles. He lost 13 in the first game, won 7 in the second, and now he has 45. How many did he have before you started?” the simplest base relations are represented in multiplicative structures. In this way it is easier for the student to identify, or in his case, for the teacher to explain it, that if two transformations give rise to a final state, then applying the reciprocal of such transformations to that final state would allow knowing the initial state. . For example, to better understand the relationships in the following problem Figure 2. Example of a sagittal diagram to represent states and relationships of a problem. Adapted from Vergnaud, in press, p. 181 Machine Translated by Google Figure 3. Relationship diagrams of the conceptual field of multiplicative structures (Vergnaud, 1990). Finally, in the fourth scheme, the relationships of what we know about the rule of three are represented. It is about the relationship between two proportional variables that, knowing this relationship in one type of measurement, can be applied reciprocally to the other to find These schemes express the relationship between two proportional variables. In the multiplication scheme (upper part of the figure) of the four measurements, the unit value is known and the unknown data is the value of c. Which can be deduced from the scalar operator that makes the value of bo go from unity to the proportional function operator that makes it go from one type of measurement to another. To explain the transformation in mathematical knowledge from interaction with someone more expert, Vergnaud takes up the notion of development zone. the missing value. In division-partition, the unit value that can be obtained by applying the scalar operator that passes from unit to b (multiplying) but now in the opposite direction (dividing) is unknown. In the division-quotation (or grouping) the unit value is known and the value of c is unknown, which can be obtained by means of the proportionality coefficients between the two variables or with the scalar operator. 52 Machine Translated by Google • Its generative aspect involves rules to generate the activity, specifically the sequence of actions, information gathering and controls. aspects: • Its epistemic aspect involves operative invariants, specifically concepts-in-act and theorems-in-act. Its main function is to collect and select relevant information and infer goals and rules from it. For example, substituting the theorem-in-act ”the largest number goes inside the little house” by ”the dividend can be less than the divisor” is a progress in knowledge, generally the product of facing various situations, directed or not to such end, by the teacher. Vergnaud (2009) proposes that if the theory that knowledge is an adaptation process 26 is assumed, then the question must be answered: what is it that adapts and to what? • Its intentional aspect involves one or more goals that can be 53 He considers that the most reasonable answer is that what adapts are the forms of organization of the activity, that is, the schemes, and they adapt to the situations. developed into subgoals and anticipations. He takes up the notion of schema from Piaget, complements it and enriches it. For example, he departs from the fundamental distinction between epistemic subject-object and focuses more on the observation of the subject ”in situation”, that flesh and blood subject of constructivism contemporary functionalist. According to him, the schemes comprise several next proposal by Vygotsky (1996), defined as one in which the apprentice knows how to do something with the help of another, but cannot do it completely alone. It is situated between the current level of development and the level of potential development; however, it tells us that this zone of development can be better understood if what it consists of is specified. In this regard, Vergnaud (2006) proposes that the current development would be the repertoire of schemes that a subject has to face certain situations and the potential development would be made up of those that the subject could strengthen or the new ones to generate when facing a set of specific situations. (of a conceptual field) that, with the help of the teacher or some other person with this role, he could achieve. II.3.2 SCHEME Machine Translated by Google 54 Knowledge is derived from activity and is organized in schemas or, more specifically, in its epistemic components. Vergnaud distinguishes between theorem-in The theorem defines it as follows: • Its computational aspect involves inference possibilities. They are essential to understand that thought is made up of intense computational activity, even in seemingly simple situations, and even more so in novel situations. When facing ”situations”, ”tasks” or ”problems” we need to generate goals, subgoals and rules, as well as properties and relationships that are not observable (Vergnaud, 2009, p.88). By definition, a theorem-in-act is a proposition held to be true in the activity. In fact, the study of the development of competences in the course of learning or in the course of experience shows that the same concept can, depending on its state of elaboration, be associated with more or less numerous and more or less rich theorems. The range of theorems-in-act that can be associated with the same concept is generally very large, particularly in scientific and technical disciplines, in such a way that, frequently, there is no act and concept-in-act. Gérard Vergnaud proposes a classification of situations based on the mathematical relationships and the conceptualizations involved in each of them. It gives special emphasis to the notion of representation and its different planes that are homomorphic with each other and with reality; For our analysis of the procedures, its notion of schema is very relevant to understand the answers of the students and that is why the theory of conceptual fields seems to us to be a very useful tool in order to explain the resolution processes based on the conceptualizations mobilized and the representation systems used by students in the proposed experimental situation. It is for this reason that this problematic situation and the resolution processes by the students and the underlying conceptualizations are analyzed in the light of Vergnaud’s theory of 27 conceptual fields (1990; 2009). II.3.3 THEOREMS AND CONCEPTS-IN-ACT Machine Translated by Google 55 According to what is mentioned in this fragment, a theorem can be true or false because it is a proposition (or a statement). A concept is not a statement, it is a category, it cannot be considered true or false, but only relevant or not relevant to the situation. It clarifies that theorems-in-act can be false but be considered by the student (or the person) as true (Vergnaud, 2009, p. 88). We had the opportunity to personally ask Vergnaud if it was necessary to express the theorems-in-act mathematically and he said no, that they are affirmations, or implicit beliefs and can be recognized in different fields, not only in the field of mathematics. He gave us the following example: Regarding marriage, the concept of husband and wife entails a series of affirmations, beliefs that are assumed to be true for the subject and from there he has certain expectations, forms of behavior, rules of action, etc. meaning to declare that such a subject understood such a concept. It would be necessary to be able to specify in each case which theorems-in-act he is capable of using in the situation. Let us not forget that theorems are propositions and not concepts, even though they are evidently constituted by concepts. Inferences are relations between propositions and are chained by metatheorems (or higher order theorems), such as Aristotelian syllogisms or the transitivity of order relations: a>b and b>c => a>c. (Vergnaud and Recopé, in press, p. 307) Some examples of theorems and concepts-in-act can help to understand these notions. In relation to algorithms, some students actually believe that all multiplication results in a number greater than those multiplied (which is true only for integers) or that the result of subtraction is always less (which is true when not negative numbers are involved). Another theorem-in-act is to consider that in division the largest number will always be the dividend and the smallest will always be the divisor. These statements are considered true by students and they are not always aware of them; they are theorems not externalized and built in action, they are theorems-in-act. Propositions are composed of concepts with different levels of appropriation, some properties of concepts may not be able to be expressed through language or, like theorems-in-act, not be quotients of them: they are concepts-in-act. Machine Translated by Google II.3.4 LINGUISTIC MEANINGS theorems. This statement, considered by the authors as an implicit primitive model, from Vergnaud’s perspective would correspond to a theorem-in-act, which also has the characteristic that it generally cannot be made explicit by the subject. It has a behavioral basis because it is built in action and for this reason he assigns it the name of theorem-in-act or in action. Thus, although both notions can refer to the same phenomenon, Vergnaud’s perspective is chosen, who integrates this notion as part of the operative invariants that in turn are components of the scheme. However, during the analysis of the results, some coincidences with those obtained under the notion of tacit or implicit models by Fischbein et al. (1985). So, any concept has tied to it a certain number of theorems in action that are more or less explicit and derived from experience, the cultural environment, etc. of which one does not become aware until facing a particular situation that ”falsifies” said statements. This notion of theorem-in-act is 28 analogous to that of implicit primitive models proposed by Fischbein, Deri, and Sciolis (1985). They maintain that some primitive behavioral models come into play in arithmetic operations that make students, even if they know how to divide conventionally, to cite an example, be influenced by one of these models and make mistakes. One of these implicit models is that in division interpreted as distribution (partition) and in division interpreted as grouping (quotation), both the divisor and the quotient must be smaller numbers than the dividend (p. 14). On the other hand, Vergnaud (1994) raises the need to analyze and classify the variety of linguistic and symbolic signifiers that we can use when we communicate and think about the conceptual field of multiplicative structures. He considers that an essential empirical and theoretical task for researchers is to understand why a particular symbolic representation can be useful, under what conditions, when and why it can be adequately replaced by a more general and abstract one. He proposes a scheme to exemplify the different representation systems based on the planes of representation in which they are located (See Figure 2). It also expounds the need to pay close attention to the comparative difficulty of different kinds of 56 Machine Translated by Google Figure 4. Representation systems. Taken from Vergnaud (in press, p. 183). The psychological current that allows us to account for these processes arising when solving a task in a short period of time is Situated Microgenesis proposed by SaadaRobert and Balslev (in press). Relevant aspects of it and the clinical/critical method proposed by Piaget will then be reviewed to support the methodology used in the present study. problems and procedures, as well as the different verbal and written expressions produced by the students (Vergnaud 1994, p. 43). In Figure 4 four representation planes are shown; the plane of the iconic representation of groups of objects, the plane of the sets, the cardinals and the written numbers. Each of these planes involves different forms of symbolization although they are homomorphic to each other. It means that each representation system has the same structure as the others but they are not equal to each other (they are not isomorphic) some properties are preserved but others change. 57 Machine Translated by Google CHAPTER III. Methodology III.1 METHODOLOGICAL DESIGN III.1.1 PROBLEMATIC SITUATION The second phase consisted of conducting clinical interviews with 30 students who gave interesting answers to understand in depth the relationship between the different representation systems used and the justifications they give for using them. The investigation was divided into two phases: the first was the group application of a problem from the conceptual field of multiplicative structures from which 4 versions were generated that are described later. The basic problem is the following: It is known that the sociocultural contexts of the students favor the type of situations they face on a daily basis, and therefore these contexts influence the development of the skills needed to solve them satisfactorily (Vaca et al., 2010). We also know that there are a wide variety of conditions in schools (Rockwell, 2005), and different levels of teacher performance that could affect the achievement that students can achieve in learning mathematics. In addition to the fact that Mexico moved towards a curricular change based on competencies and that transition 29 has caused confusion in the actors of the educational system at its different levels, but mainly it has caused confusion in teachers, who are attributed the responsibility of the low scores obtained on standardized tests. However, for this work we will only focus on the resolution process to identify the main difficulties that students face when faced with these problems in the conceptual field of Hector walks 35 meters and takes 70 steps. On average, how big are your steps? This problem belongs to the conceptual field of multiplicative structures (Vergnaud 1990, 2009) because the base relation is quaternary (four quantities are related) and because of the isomorphism of measures that relates two measures of a different nature, in this case number of steps and number of meters. 58 Machine Translated by Google the multiplicative structures derived from one of the items of the PISA test. retain a certain degree of difficulty and that could promote different strategies of This problem and its versions are an adaptation of the step problem, reactive resolution and forms of representation. used in the PISA 2003 test (National Institute for Educational Evaluation, 2013): Since the original problem requires mastering algebra content that is not 59 are part of the curricular structure of the primary level, an adaptation was made that Image 4. Steps. Item released from the PISA 2003 test. Taken from INEE, 2013. Machine Translated by Google III.1.2 ANALYSIS OF THE PROBLEM dimension to try to define what a step is. However, defining it is not trivial and requires certain considerations. Since it is about establishing the relationship between the number of steps and the distance traveled in meters to calculate the average size of each step, this problem is located in the conceptual field of multiplicative structures in the types of isomorphism problems of measures (Vergnaud 2004, p. 218). The Dictionary of the Spanish Language (Royal Spanish Academy, 2013) contains What is a step? Figure 2 shows the scheme that represents these relationships. 60 This is a problem that looks for the value of a part or an object, in this case the average size of the steps. A step can be considered to be something common when talking about walking, without Before continuing with the analysis of the problem, it is necessary to make a small Figure 2. Diagram of relationships corresponding to the problem of steps. Machine Translated by Google 6. m. Regular movement with which an animal walks with legs, raising its limbs one by one and without giving rise to any jump or suspension. 5. m. Roman step. To take advantage of the benefits of graphical representations, which we believe help us to carry out this small analysis, we made the following scheme (See Figure 3). 4. m. Mode or way of walking. If it is a question of measuring the advance with a step, the head of the person who walks can be taken as a reference point and draw a line perpendicular to the ground that will be the starting point and when moving one foot forward, it would have to be drawn another line from the center of the head to the ground to determine the point of arrival and with it the actual distance advanced. 61 3. m. Continuous movement with which an animated being walks. 1. m. Successive movement of both feet when walking. As an instrument for measuring through displacement, some clarifications must be made: 2. m. Distance traveled in each movement while walking. Passed. We can consider the step as a movement when walking or as 30 a unit of measurement. As for the first, it is worth considering whether a step is the movement of only one foot (forward or backward) or the movement of both feet should also be considered. Regarding the second consideration, it is essential that, as a measurement instrument, it remain invariant (that is why in the problem we use the expression ”on average”) and it must be determined from where to where said measurement will be made. meanings to the term, of which 8 can be used in the context of the problem: 11 m. Each of the advances made by a counting device. 9. m. Print or footprint that remains printed when walking. Machine Translated by Google Figure 3. Scheme for defining a step. Source: self made. of a single foot, the distance traveled is from line A to line B. If we consider that the upper drawing indicates the point of origin of the displacement of one foot that culminates in the drawing below, the following cases can be defined: Case 3. If we take the person’s feet as a reference, we must choose a point of reference, for example the heel of the feet. When moving a single foot, the distance traveled would be from line A to C, or if we chose the toe as reference, the distance traveled would be from line B to line D. Both are the same size and the distance would be the same as if both feet are moved and the head is taken as reference (Case 2). Case 2. If we again take the head as a reference and the other foot is moved to reach the first one already displaced, then the distance traveled would be from line A to C , which would be twice the size of the first one but the displacement of both is required feet. Case 1. If we take as reference the head of the person and the displacement If we arbitrarily consider that the average size of a person’s steps is half a meter (Historically it has been calculated that it is approximately .7 m as an anthropomorphic measure), this distance is achieved in cases 2 and 3 because in case 1 the distance traveled would be half, 25 cm. 62 Machine Translated by Google After this note, we continue with the analysis of the problem. The first requires applying a scalar operator. If in the steps column (See Figure 4) the scalar4 operator (x70) changes from 1 step to 70 steps, then in the meters column the operator (:70) is applied, which is the inverse operator and will go from 35 meters to the unit value that acts as unknown. The second procedure (See Figure 5) is to apply the function operator (:2 meters/step), which converts 70 steps to its measurement in meters, that is, 35 meters, which implies dividing 1 by 2 to obtain the unit value. There are at least two procedures to solve this type of problem (Vergnaud 2004, p. 202): In the text of the problem it is mentioned that Hector walks a distance of 35 meters and takes 70 steps. It means that for this condition to be fulfilled, we must assume any of the cases 2 or 3 as a step because with case 1, with 70 steps the distance of 35 meters would not be reached. 63 Figure 4. Diagram of vertical relationships, with scalar operators. 4 Vergnaud represents the operators with circles in the body of the text as they appear in the diagram, however for typographical reasons we will represent them with parentheses. Machine Translated by Google Figure 5. Diagram of horizontal relationships, with proportional function operators. If we substitute the values of the problem in the previous approach we would obtain: This procedure is more complex than the first because the same relational calculations are not involved and because it is a function operator 31 that passes from one measurement category to another. 70 steps = 35 meters ÿ 1 step = 35 meters / 70 ƒ(nx1) = nƒ (1) ÿ ƒ(1)= ƒ (nx1)/n In order to make a demonstration of these solutions, the analysis of the mathematical properties that Vergnaud (2001, p. 215) makes in this type of problems is taken up and adapted, to find the solution of this one, where he considers that it is necessary to recognize a property of the linear function ƒ that joins the measure of the distance covered with the corresponding number of steps. This means that the size of n times a step (70 steps) is equal to n times the size of a step (35 meters), therefore the size of a step is equal to the size of n 64 times a step (35 meters) divided by n times (70). Machine Translated by Google Another possibility in relational calculus that Vergnaud analyzes is to operate on the proportionality coefficients between the two variables (horizontal relationships in the scheme. See Figure 7). 65 These relationships operate under scalar quantities, that is, dimensionless. If the ratio of a step to 70 steps is 70 times more (the scalar operator x70 is applied), then the unit value of a step is obtained by applying the reciprocal of that ratio. The value of a step is 35 meters “70 times less” or to be more precise with the language: 70 times less (the inverse scalar operator (:70) is applied). The solution procedure of scalar type [vertical in the schematic] ) establishes the relationship between magnitudes of the same type. Steps with steps and meters with meters. Of course, when students face this situation, if they were able to recognize these relationships and make these deductions, it does not necessarily mean that they can express them in natural language; It is then a question of knowledge contained in the schemes but at an operative and non-predicative level, that is to say, they are theorems and concepts-in-act. The graphical scheme that shows this relationship of the linear function would be that of Figure 6. Figure 6. Diagram of relationships of the linear function. Machine Translated by Google Figure 7. Diagram of relationships operating on the coefficients of proportionality. ƒ(n) = 2n(1) ÿ (1) = ƒ(n)/2n If the reasoning operates on the proportionality quotient of two different magnitudes, it is identified that one is twice the other; then, the relationship to go from 35 meters to 70 steps is the operation of multiplication x2, but according to Vergnaud, this multiplication does not mean two times more but rather a coefficient of proportionality that joins two variables, one with the other. another (2 steps per meter), that is, a composition of measures. It means that the other relationship to go from a step to meters must be applied the inverse operation that would be (:2), which does not mean two times less, but rather divide by two meters per step. The result would be 0.5 meters. The composition of measures could be equivalent to what Schwartz (1988) proposes as ”intensive measures” (derived from proportional relationships) as a quotient of two extensive quantities (subject to additive relationships). However, since Vergnaud’s proposal is used as a theoretical reference, it was decided to use his The functional operator is constituted, according to Vergnaud (2001), at a more elaborate level, since it implies not only the notion of numerical relation but also that of quotient of dimensions. Until now there is no data that any student has opted for this procedure. The theorem on which this reasoning rests is stated by Vergnaud (2001) in these terms: 66 Machine Translated 32 by Google magnitudes. terminology. In addition, it is considered that the notion of composition of measures is didactically more productive than the one proposed by Schwartz of intensive measures. Therefore, the problem thus posed to the students has the following characteristics: These are four versions of the problem already analyzed. Each version presents some modification that allows us to observe very specific aspects and we initially consider that each one has a different level of difficulty: due to the numerical values used and the transparency or opacity of the double/half relationship and the presence in two versions of unnecessary information or useless that we call a ”distractor” (the mention of time, which is irrelevant for the solution of the problem), although the structure of the four versions is the same and has already been analyzed. In addition to the above, we included the variable ”availability of the calculator” considering that if some of the difficulties experienced by the students were related to the lack of consolidation of the algorithms, then the group of those who had it at their disposal would reflect significant differences in relation to the group that did not have it. • The number of steps is twice the number of meters, a relationship that children identify but that in many cases is not enough for them to make the appropriate calculation and reach the expected result. • It is located in the conceptual field of multiplicative structures. • Relationships are established between four pieces of information: two explicit (35 meters and 70 steps), one implicit (the unit value of the step) and the unknown (the measure of the step). 67 • It is a problem of isomorphism of measures of the division-partition type. • The corresponding division is with a decimal quotient less than one. • The level of difficulty is high because the unit value of one of the III.1.3 INSTRUMENTS Machine Translated by Google problem versions In one minute, Hector walks 20 meters and takes 40 steps. On average, how big are your steps? Version A. With distractor (”in one minute”) and with a 35/70 ratio. The number of students who faced these versions of the problem are 329: 161 are women and 168 are men. These students belong to the last grade of primary and secondary school in five public schools in the state of Veracruz, three primary schools (one rural and two urban) and two secondary schools (one from a rural context and the other from an urban context). The distribution of students by school and by gender is presented in the Version D. Without distractor and with a 20/40 ratio. (S/D, 20/40) Version B. Without distractor and with a 35/70 ratio. In one minute, Héctor walks 35 meters and takes 70 steps. On average, how big are your steps? Table 2. 68 Hector walks 35 meters and takes 70 steps. On average, how big are your steps? Hector walks 20 meters and takes 40 steps. On average, how big are your steps? Version C. With distractor (in one minute) and with the 20/40 ratio. Table 2. Distribution of students by gender and school III.1.4 PARTICIPANTS 26 18 Elementary A Urban 31 70 Secondary B Rural 17 Total general 25 Elementary C Rural School Women Men 21 58 122 35 329 Elementary B Urban 64 168 69 Secondary A Urban 161 42 57 Total general 27 Machine Translated by Google On average, primary school students are 11.9 years old and secondary school students are 14.4 years old. The ages vary between 10 and 16 years as shown in Table 1. In The application of the instruments was carried out in 33 their classrooms at a time kindly granted by the teachers. In total, we worked with 13 groups from the five schools. Half of the groups were distributed a calculator that they had at their disposal so that they could freely use it if they so decided. The other half of the groups did not have access to the calculator. 69 (in white) 172 Total general 98 12.7 11 4 98 13 6 Secondary 55 1.8 5 N 16.7 6 N 3 14 5.1 329 55 3 31.0 Age in years 42 10 0.9 10 16 7 1 6 12 1 41 29.7 Primary N Total general 17 98 % 102 1.8 15 157 100 III.1.5 APPLICATION OF THE INSTRUMENT Table 1. Distribution of student ages Machine Translated by Google Table 3. Distribution of the groups and the availability of a calculator. 0 Secondary B 32 Total general 0 25 0 B 0 0 Elementary A schools G 0 0 H 22 17 J B 9 Elementary B 20 With calc. B B 0 0 29 Sin calc. 24 A 0 18 High School A 0 19 173 C 34 groups A I 0 A A 9 156 36 Elementary C 35 Students were given a sheet with only one of the four versions of the problem. Said sheet was placed inverted so that when it was finished distributing to the entire group, the instruction was given to turn the sheet over and everyone would start at the same time. They were asked to solve the problem with a pen to avoid erasing and if they made a mistake they could cross out what they wanted and continue elsewhere. These graphic traces could be relevant to us. The groups were organized in such a way that men were located at one end and women at the other, in order to distribute the versions of the problem among the students and have relatively equal subgroups in number. 70 The distribution of the groups according to the use of the calculator appears in Table 3. Note: cal.: calculator In the case of elementary school C, which has three groups of sixth graders, group a was allowed to use the calculator, group b was not, and in group c only half of the students were allowed to use it. Machine Translated by Google III.2 CLINICAL INTERVIEWS 5 Thanks to Mr. Francisco Javier Martínez Ortega, who collaborated as an assistant in the field work for the application of the instruments, as well as in the video recording of the interviews. This support was required due to the difficulty of recording both the written productions of the students and the verbal and gestural expressions that could give indications of the meanings mobilized during the resolution of the problem. The instruction was given for the students to fill in the identification data The criteria for choosing these students were the following: firstly, it was sought that there were students in the 6 categories into which the responses of the students were classified in the experimental phase (See Table 9, page 63): on the sheet and subsequently answer the question. 3. Correct numerical result but no reference units 1. Correct answer It is important to highlight that the situation of application of the instruments occurs in the school context, in the presence of the teachers and sometimes with the directors of the schools present, who present the applicators to the students5 . The instructions given to the students, the arrangement of the seats and the care of the applicators to deliver and collect the instruments are typical characteristics of a school evaluation context. Therefore, it is assumed that in this situation, the student’s responses are mediated by a didactic contract (Brousseau, 1997). When a student finished, they were asked to turn their paper over and quietly wait for all their classmates to finish. Only until the 34 last student finished, were the sheets collected in the same order in which they were handed out. 4. Inversion of data in division (with reference units) 71 2. Difficulties only with units of measurement Subsequently, 30 interviews were conducted with students who participated in the group application described above. 13 students from the third grade of secondary school and 17 from the sixth grade of primary school were selected. Machine Translated by Google III.2.1 PROCEDURE First of all, the student was thanked for his participation, he was informed that the intention of the interview was to find out how he solved a mathematical problem, rather than whether he gave a correct answer or not. It was emphasized to them that it was not an evaluation and that their result was not going to be reflected in their grades. What we were interested in was knowing if the problem was difficult or not and why. Even with these clarifications, some students expressed nervousness, which decreased as the activity developed. One of the questions that they were usually asked when we noticed any nervousness or little interest in the activity was about the class their group was in at that moment and if they preferred to return to their class. Only one sixth grade student preferred to return to his class and not participate in the interview. 5. Inversion of data in division (without reference units) 6. Lack of understanding of relationships between data Subsequently, he was given the sheet with the version of the problem that he solved in Another criterion used was to select the answers that were considered interesting from the point of view of the graphic representations used or the answers given, either because of their originality or because they were not understood by the interviewer. Since in the analysis of the responses, inferences were made that needed to be corroborated with a different methodological strategy, in this case, through clinical interviews. The interviews were conducted in spaces provided by the school principals. They were generally spaces for the activities of the teachers or computer centers in which there were generally teachers carrying out some activities, so there is often interference in the audios, in addition to the sounds of the activities carried out by the students outside their classroom. of classes. As already documented (Vaca et al., 2010), one of the characteristics of public schools is that they are noisy. 72 Machine Translated by Google III.3 THE CLINICAL METHOD The interviews were videotaped and for this, as already mentioned, there was the support of an assistant, who operated the video camera with the intention of recording the detail of the written productions made by the students, the movements, indications, gestures that could give indications of the representations made during the process of solving the tasks during the interview. The reasoning routes were highly variable due to the justifications or specific difficulties experienced by the students during the resolution of the problem and the development of the interview. In some interviews, topics were explored in greater detail than in others; such as fractions, decimal numbers, proportional relationships, writing the division algorithm and units of measurement, according to the relevance given by the interviewer-teacher at that time. the experimental phase. They were asked to read the problem again and to solve it again. When they concluded the resolution, they proceeded to explore the meanings attributed to their graphic 35 productions or to the result obtained. Each student represents a different case, with reasoning paths that may coincide with other students on some points and not on other points. On the one hand, its autonomous resolution was sought without the intervention of the interviewer, later we sought to know their conceptions regarding the general themes and finally we gave ourselves the freedom to follow the reasoning and procedures that the student manifested, to try to understand their resolution paths. and, to the extent possible, the level of consolidation of the concepts evoked. The clinical/critical method proposed by Piaget has been one of the main instruments for collecting data in psychogenetic research of the Genevan school. Despite some criticism and its long history, it is still valid. As demonstrated by Bond and Bunting (1995) who carried out a study in which they affirm that the results obtained are sufficient to convince the skeptical empiricists of the validity of the 73 Machine Translated by Google He considered that the form and function of thought is expressed when the subject interacts with other children or with the adult and that, although the interaction can be observed from the outside, the content could not be discovered depending on the subjects and the objects of representation (Piaget , 1978). But, with Vergnaud’s proposal (in press) of relational calculus and calculable representation, the analysis of the situations in which these interactions take place makes it possible to more clearly infer said contents. Piagetian theory when it was criticized for using a very small sample of subjects, unlike the statistical treatment of populations in Anglo-Saxon studies. Piaget (1978) considers that this method of data collection retains the advantages of both observation and tests, but without their disadvantages, such as missing essential problems and spontaneous interests. 74 The art of the clinician consists, not in making people answer, but in making people speak freely and in discovering spontaneous tendencies, instead of channeling them and putting them on the dam. It consists of putting every symptom in a mental context, instead of abstracting from that context. (Piaget, 1978, p. 258) But unlike the other methods, this one is not easy to carry out; requires training and certain characteristics on the part of the clinician: One of the objectives of the clinical interview as we use it will be to propose problematic situations that can trigger resolution procedures in the student through which it is possible to infer the theorems- and concepts-in-act contained in their activated schemes to face it. , and make them explicit as much as possible. Piaget expressed it in other words: The content is a system of intimate beliefs, and a special technique is needed to discover them. It is above all a system of tendencies, of spiritual orientations, of which the child himself has never been aware and has never spoken (Piaget, 1978, p. 258). Machine Translated by Google III.4 SITUATED MICROGENESES Microgenetic studies, for us, represent a state of the evolution of Piagetian constructivism, it is a research perspective with at least 5 currents of study, all of them have as their object of study to understand how the subjects perform in the activity in a certain situation. , that is, how their schemes are mobilized, updated, combined and built in action. These studies are related to activity theory and socioconstructivist theories. They also give a central role to 36 language as a mediator since the interactions occur mostly through linguistic signifiers, as well as the interaction between subjects and with the object or situation. Indeed, the object of study is both the construction of knowledge and the way in which formal and informal knowledge is presented by the most expert participant, and the way in which it is transformed into internalized knowledge by the apprentice. Situated microgenesis is thus characterized by a double construction process: an asymmetric co-construction between the participants, regarding knowledge, and the asymmetric co-construction of a zone of understanding, ensured by the exchange of meanings between them (SaadaRoberts, M. and K. Balslev, in press, p 305). 75 The current of these studies on which we base ourselves to carry out this research and which is the last one developed up to now is that of situated microgenesis that seeks, in addition to the aforementioned object of study, to understand how meanings move through analysis. of the microprocesses and the interactions of the student with the teacher or whoever assumes that role in actual teaching situations in a school context. The zone of understanding is understood as the period of interaction time during which the teacher’s didactic intention is expressed (verbally or not) and is understood by the student. There are, of course, important differences between the mastery of knowledge by the teacher and the student, but the task of mediation on the part of the teacher is to carry out the transposition so that it can be apprehended by the student, in case it is successful and is at the student level, then you can talk Machine Translated by Google They are in a zone of understanding. Sometimes it happens that the teacher’s interventions are not fully understood by the student or that he interprets them in a different way from the teacher’s intentions. In these cases, they are not considered to be in a zone of understanding. 76 Machine Translated by Google III.4.1 General aspects of microgenesis For the present investigation, we consider as an object of study the one that is The evolution of genetic psychology has studied the processes of construction of knowledge by the ”epistemic” subject, through the great periods of development (stages) and now also by the study of the microprocesses of knowledge acquisition by a subject. “psychological” through the study of microgenesis (Inhelder and Caprona, 2007). 77 outlines the situated microgenesis (Saada-Roberts, M. and K. Balslev, in press): The object of study of microgenesis is different depending on the current in which it is located: These studies, although originally seeking to find analogies between the knowledge construction processes of macrogenesis but on a smaller scale, have differed in that they are now not about analyzing what a group of subjects do according to their level of development ( epistemic subject) but to analyze how he updates his knowledge in the face of a specific task in a particular situation and conditions. The object of study no longer directly addresses development processes, but rather the construction of cognitive representations, as instances of organization of previously acquired knowledge (development pole) with the properties potentially contained in problem solving situations ( pole of situated learning) (Saada-Roberts, M. and K. The reciprocal adjustment between the adult and the child. The analyzes present results in terms of the diversity of actions produced by the children, 37 the more or less complex linkages between their actions to achieve a goal and the effects of these actions on adult interventions, as well as the reciprocal effects of these actions. latest in children’s learning. The question of reciprocal adjustment between the participants in the construction of knowledge is what constitutes, from our point of view, the originality of these works (P. 300). Balslev, a prensa, p. 298). Machine Translated by Google 78 Only under this condition can such a study be linked to the explanation of the microprocesses of knowledge acquisition. Regarding the situated character of microgenesis, it refers to the didactic dimension of this acquisition, in other words, to the triadic study of the construction of teaching and learning knowledge as they function in situ . More precisely, situated microgenesis deals with the didactic dimension through the analysis of the progression of knowledge linked to the exchange of meanings between participants, in real time and place (SaadaRobert and Balslev, in press, p. 293 ). This flexible modality of the clinical interview reminded us of a work by Blanche Benveniste and Ferreiro (1998), who, when investigating the expression of denial in Spanish-speaking children to reflect on writing, proposed to the children the game of ”saying things backwards”. ”. For example, one of the questions asked to the students was: A first definition of microgenesis is ”the study of knowledge acquisition processes in a short time and in a particular situation among the possible acquisition situations, solving problems by instruction, by free exploration, etc.” (Nguyan-Xuan, 1990, p. 197 cited in Saada-Robert and Balslev, in press, p. 291). To this definition, the authors add the didactic dimension to conform situated microgenesis: In this research, the interviewer also adopts the role of teacher, who during the interaction phase, in addition to clinically exploring the processes of solving a mathematical problem by the students, seeks to present situations that lead to the confrontation of their ideas, take them to a certain limit so that, as far as possible, they are made explicit, tested and modified to generate new and more general ones. That is, work in the zone of proximal development through interventions that require the student to update or modify their schemes for the specific content of the task performed. During the interview, the interviewer proposes new problems from different fields and even some that could be judged as ”absurd”. Some of them achieve the purpose of making the student reflect on the mobilized concepts. On other occasions, these problems do not achieve this objective, given the nature of improvisation based on the reasoning routes shown by each student. Machine Translated by Google The units of analysis for this study are determined by the resolution schemes that the students mobilize, respecting their sequence. Since these schemata are the invariant organization of behavior in a class of situations and the students only faced a problematic situation, we cannot accurately infer them. However, we assume that in solving the problem one or more schemes are applied, whose components include goals and sub-goals, inference, operational invariants and action rules, as mentioned above. What is the reverse grape? The most frequent response was “uvo”, which led the authors to discover the immense potential for reflection in very young children regarding the morphological structure of their language. In the example, 38 the morphological opposition of feminine/masculine, without any semantic correlate (”uvo” does not exist in the language). What could be considered a very general slogan, even interpreted as absurd, allowed the authors to inquire about the knowledge that students put into play, for example: deciding on a semantic or a formal answer, mastery of the morphology of the language and contributed to building indices on the representation of the word unit outside the written sphere. Therefore, to be consistent with the microgenetic analysis and attend to the temporal dimension of the resolution process, it was decided to determine the units of analysis through the spontaneous segmentations that arose during the process. Data analysis We have proceeded in a similar way when formulating problems for the children that seem absurd (dividing children between palettes) but that allowed them to reflect on the elements of the graphical algorithm of division and its distribution. Based on these antecedents, a clinical interview and a microgenetic analysis are carried out with the purpose of making an investigation of the level of construction of the mobilized mathematical concepts, inferred from the exploration of their resolution procedures and from the linguistic interactions between the participants. students, the interviewer-teacher, the problem and the specific situation. 79 Units of analysis Machine Translated by Google • Those of knowledge in operation. problem solving by the student. These segmentations are generally related to sub-goals, small detours or sub-procedures that occur while the subject seeks to achieve the main goal in the problematic situation, that is, to find the solution to the problem. Some of these sub-procedures may consume a large part of the interview or be very brief; In all cases, the corresponding segmentation is marked to determine the beginning and end of each unit of analysis. • Those of the progression of knowledge in the form of microgenetic “sequences”. • Those corresponding to the direction in the process of construction through the Situated microgenesis is not supported by an artificial simulation device, but is methodologically based on the analysis of interactions, mainly but not exclusively verbal, interactions whose hidden meanings one tries to reconstruct, depending on the context in which the participants evolve. ” (P.301) According to Saada-Roberts and Balslev (in press): • The relevant indices to explain an area of common understanding among the participants, the dynamics of which vary from one sequence to another. Regarding the indices of knowledge in operation, we return to Gérard Vergnaud’s theory of conceptual fields to identify the mobilized mathematical concepts, their relationship with other concepts and try to infer their theorems and concepts-in-act during the sequences. Regarding the indices that guide the meaning in the construction process, we pay special attention to the verbal and gestural expressions and graphic productions, both of the student and of the interviewer, that is to say, to operational indices 80 specific enunciative modalities. We have taken into account the following operational indices proposed by Saada-Robert and Balslev (in press, p. 307) to account for the construction of knowledge through the meanings between the student and the interviewer in a zone of understanding: Machine Translated by Google the predicative part of knowledge. Those related to the progression of knowledge 39 were carried out by signaling the segments of the microgenetic sequences, as already mentioned in the previous section. The progressions are expressed in the knowledge mobilized when they occurred. 81 Machine Translated by Google parts of the total) these problems present difficulties for them to solve. Are analyzed students responded adequately, which means that for the rest (two thirds 82 reference units (half meter or its equivalent). One third of the statistically significant (See Table 2). secondary school obtain better results than those in primary school. investigation, that is to say, that they indicate the measure of a step by means of the magnitude and the How many students solved the problem in the expected way? Of the total of 329 indeed there are more men who arrive at the correct answer and the difference is By educational level, the results of Table 3 indicate that students of students, 113 (34%) gave the answer that is considered correct for the purposes of the Regarding the results obtained by men and women, it is observed that Note: Test Chi2 = 4.663, sig. 0.031 location, calculator availability, and problem versions. Below are the results based on some variables such as sex, educational level, Female Sex 46 Masculine 113 329 67 113 115 Total 216 Incorrect Correct Grand Total 101 216 CHAPTER IV. Results of the experimental phase 47% 51% 71% 53% 49% 49% 100% 41% 100% 100% 100% 100% 40% 34% 29% 66% 100% 60% Table 2. Results by sex IV.1 GENERAL RESULTS Machine Translated by Google more students in rural locations considered the real feasibility of their answers; better deal with problems of this type. However, it is necessary to highlight the In a research report, Chain, et al. (2009) analyzed some items of the were more likely to have constructed or enriched schemas for It seemed strange to them and they also did not take into consideration its relationship with reality. that others in high school did not make it. required the calculation of the weight of a cow in grams or the one that requested the calculation of the In primary school, the majority had an incorrect result (79%). On the other hand, in the fact that there were primary school students who gave a correct answer, while ENLACE test and reported that some items were absurd, such as the one 83 As expected, more high school students achieved a correct result, some difference because, in a previous study (Vaca et al., 2010) it was reported that The results obtained in the rural and urban localities are practically the same as those capacity of a water tank in milliliters. Surely these reagents were created by the secondary the percentages are similar; almost half solved it correctly. same (See Table 4) and there are no significant differences. however it was expected opportunity to face a greater number of problematic situations and therefore unlike those who, when obtaining steps of 2 meters or 2 cm as a result, do not compared to those in primary school. To some extent it is obvious since they have had the 100% 100% 48% 100% 79% 49% 52% 68% 72% 51% 32% 37% 21% 63% 28% 100% 100% 100% Table 3. Results by educational level 136 Total 216 Total general 329 Level 77 36 Wrong right Primary 113 157 172 Secondary 80 Machine Translated by Google 34% 100% 100% 100% 67% 100% 66% 35% 100% 65% 27% 100% 72% 28% 34% 28% 72% 72% 156 81 237 Rural 60 Urbana 32 Total general 216 92 Location Incorrect Correct Total 113 329 designers under the idea that the student would show 40 the ability to operate with empirical feasibility. large numbers and also in situations of ”everyday life”, although in it it is not Note: Chi2 test =0.011 sig. = 0.917 These data in Table 4 indicate that there are no significant differences between the The students are then familiar with problematic situations the cows are not weighed in grams nor is the capacity of the water tanks specified in milliliters. localities, at least in terms of the final result obtained. 84 whose results should not necessarily be anchored in reality and therefore this Regarding the availability of the calculator, these results (See Table 5) show that there is no significant difference between those who had a could lead them to not establish this common sense reference to determine their calculator and those who did not have one. Table 4. Distribution of the results by type of locality Machine Translated by Google strengthen the four basic operations of elementary arithmetic. However, in 31% got a correct answer. Of those who had a calculator, a total of 173, the become a disadvantage when high school students did not have their horizontal we see that of the 156 students who solved the problem without a calculator, use is more permitted by teachers. On the other hand, this apparent advantage may calculator does not guarantee better results if you do not properly understand the resolution difficulties. Such difficulties with the algorithm appear in the roundups Note: Chi2 =1.684 sig. 194 38% get a correct answer. These data may indicate that the use of the availability of a calculator and possible lack of practice with algorithms could cause decimal, in the quotient position, for example. Of the 216 students who did not give the correct answer, half had at their disposal prevent students from using the calculator because they feel it does not allow them to problem or it is not known how to interpret the result obtained. that some do to find the quotient of the division or in the handling of the point 85 It is possible to analyze this table in two senses: in the vertical sense we see that from Some teachers with whom we have spoken mention that in primary school correctly, 58% were able to benefit from the technological device. In the sense Secondary school most of the students use the calculator on a daily basis and their a calculator and the other half not. Of the 113 that solved the problem 100% 100% 53% 31% 38% 58% 66% 47% 62% 42% 50% 100% 50% 100% 69% 34% 100% 100% Table 5. Results depending on the calculator. 48 Total 216 329 Total general 108 Wrong right 173 Availability no calculator 113 65 156 with calculator 108 Machine Translated by Google 24% 26% 58% 21% 26% 20% 23% 20% 66% 100% 100% 100% 71% 100% 24% 28% 100% 74% 100% 26% 31% 26% 100% 30% 34% 100% 41% 29% 42% 59% 57 80 incorrect correct B (s/d, 35/70) C (c/d, 20/40) 23 Version 64 87 35 84 A 23 (c/d, 35/70) 46 32 78 329 49 216 113 D (s/d, 20/40) Total Total ”transparent” (20 and 40) more students correctly solve version D than version By joining the versions with the distracting data A and C and contrasting it with the union of the Note: c/d: with distractor, s/d: without distractor problem. Remember that the difference between version A and B is that the first second does not have it (s/d), so the latter is considered to have a lower degree of version C (41% against 29%). The data shows that indeed more students correctly solve the contains irrelevant data (one minute) that works as a distractor (c/d) and the 41 difficulty. The same is true for versions C and D. versions B and D, which do not have it, the difference between the results obtained (See table 7). version B than A (42% against 26%) and, in the same way, in the versions with quantities 86 Table 6 shows the results obtained according to the version of the Table 6. Results according to the version of the problem Machine Translated by Google Table 7. Distribution according to the versions with or without distractor 162 (100%) Sin distractor 167 (100%) versions Total (B y D) incorrect correct Con distractor 95 (58%) Total 67 (42%) (A and C) 216 (66%) 113 (44%) 329 (100%) 121 (72%) 46 (28%) numbers in the text of the problem change, from being 35 and 70 in the first ones, they change to 20 can face a problematic situation by applying guided resolution schemes The difference between versions A and B and versions C and D is that the values demonstrated that distractors significantly affect performance, in terms The difference is significant (with 0.008 of sig.) and this suggests that the students generals. are necessary. On the other hand, in the literature on problem solving, it is 87 then concentrate on finding the relationships between the data and discard the ones that do not there are no major differences. Using some data, students could modify this idea and allow them to Once again, if the versions are grouped according to the type of magnitudes, it can be seen that face various problematic situations, with variations in the relevance or otherwise of Numerical numbers could make it easier or harder to find the proportional relationship between them. appear in the text of a problem should be used in the solution. It is through and 40 in the second. This difference was made under the hypothesis that the values by the belief (theorem-in-act) that could be expressed thus: “all the data that Machine Translated by Google Table 8. Distribution according to the type of magnitudes (C y D) 216 (66%) 113 (44%) 329 (100%) versions 35/70 Total Incorrect Correct Total (A and B) 113 (66%) 58 (34%) 171 (100%) 20/ 40 103 (65%) 55 (35%) 158 (100%) of the problem and its resolution procedures. the conditions of the problem can change, if very large quantities are used or students wrote, which in some way indicate the representation that was made the reasons why practically those two-thirds did not resolve function of the magnitudes used. However, it is also known that the magnitudes students. The difficulties caused give us the opportunity to analyze which were properly. To do this, the responses that the participants received were classified into six categories. represent the relationships between the data in order to discard those that are not relevant for calculus is a more complex activity than calculus itself in With these data it can be inferred that, for this particular problem, expected because it is a ”problem” and must offer some resistance to the Note: Chi2 = 0.029 with sig.=0.865 the problem was solved correctly and therefore two thirds did not. It is The previous results indicate that a part of the students who faced as reported by Vergnaud (1994). 88 very small, decimal or integer and also depending on the domain of experience, Machine Translated by Google Table 9. Distribution of results by categories IV.2.1 RESULTS BY RESPONSE CATEGORIES IV.2 ANALYSIS OF THE DIFFICULTIES 82 23 3. Correct numerical result but no reference units reference) Total 113 7.3% 34.4% 7.0% 6. Lack of understanding of relationships between data Frequency Percentage 42 7.0% 23 2. Difficulties only with units of measurement 19.5% 100% 1. Correct answer 64 24.9% Category 5. Inversion of the data in the division (without units of 329 24 4. Inversion of data in division (with reference units) through clinical interviews in the next phase of the investigation. For this analysis For example, who answers ½ meter; the student could not do written operations and only the graphic productions of the students were available and therefore the Category 1. Correct answer classified the 329 responses of students, both primary and secondary. arrive at that result by mental calculation (without ruling out that you can do checks). information is limited. Table 9 shows the distribution of the results in six categories. HE In this category were located the answers that we considered correct (N= 113, 34.4%) It is important to clarify that the following interpretations will be sought to be confirmed by 89 and can be expressed in various ways depending on the procedure performed to obtain it, Machine Translated by Google 90 In the example (See Image 5), Brandon arrived at the correct answer, which It implies having coordinated several processes without neglecting any of them. If we resume analysis of the problem we can then make the following inferences: Picture 5. Problem A, Brandon age 11 years 8 months (11.8) primary school A (urban), no calculator The schema activated to face a situation in which it is involved class of problems where proportionality comes into play, that is, theorem-in-act of proportionality, the concepts-in-act of the problem statement (problem reading). He understood that what allows to recognize the concepts and theorems-in-act, to generate a proportionality, coefficient of proportionality, measurements, the notion of • In the first place, it has a scheme that allows it to identify at the level of resolution procedure and monitor its performance. In the following function among others. operational invariants, the relationships in the problem to locate it in the the proportionality of two variables allows you to properly interpret points these invariants are described but they are related to the Machine Translated by Google ƒ(nx1)=n ƒ(1) ÿƒ(1)= ƒ(nx1)/n That in Spanish it would be expressed (returning to the analysis that Vergnaud meters) is equal to 70 times the size of a step, therefore, the size times. Hence the 35/70 split.” [2001] makes this property) “the size of 70 times a step (35 of a step is equal to the size of 70 times a step (35 meters) divided by 70 91 found in students who have solved this problem. • Correctly identified that the time data is irrelevant and does not take it The division that it performs is based on the theorem analyzed above: have been 1/2, a procedure that is also correct and has not been done until now. • He operated with the scalars, that is, vertically in the analysis of the (50 cm). taken into account in your calculations. allows you to locate the problem within the proportionality situations. Figure 3. In case of operating horizontally, the division would have to operate now with another unit, centimeters, and write it conventionally • Established the relevant relationships between the data. Brandon’s scheme steps of different sizes when walking and cover the same distance result to whole numbers by multiplying the dividend by 100 to with the same number of steps. quantity and not a possible range of measurements that would indicate that there may be of the decimal numbers in the division. He then chose to convert the pide is the average of the size of each step of 43 Héctor, since he gives only one numerical, although it is appreciated that it had difficulties in proper handling • Was able to determine the appropriate reference unit for the result Machine Translated by Google The prototypical example is that of Miguel Ángel (11.6) in the sixth grade of primary school in decimal metric, which combined produce responses such as “5 cm”, “0.5 cm”, “5 mm”. correct numeric but assigned the wrong unit of measure. problem in the conceptual clarity of two notions: decimal numbers and the system In this category are located the results of the students who reach the result write 5 cm. as a result. In most of the answers classified in this category, a Category 2. Difficulties only with units of measurement (N23, 6.9%). they did not correctly solve the problem, because they faced some difficulty in one or quotient and properly handles the decimal point in division. However, in the end several points above. In the rest of the categories, the answers of all the students who correctly the algorithm with the support of other multiplications to calculate the recognition of the proportional relationships involved in the problem, apply a rural locality (See Image 6). The division you choose rests on the 92 • Does correct numerical calculations, although with some detours. Image 6. Example of resolution classified in category 2 Machine Translated by Google 93 decimal numbers, knows that they represent a fraction of the unit; so as a continuous quantity, in addition to conceptualizing the characteristics and logic of both the account in solving a problem is the numerical result. As Jeovany (14.0 units to the final result (See Image 7). unknown; So, only meters left. But from the experience they have had with the Accepting that it is possible to write 0.5 meters requires conceptualizing the meter decimal number. Then they deduce that the unit must be centimeters, which are importance of specifying the type of magnitudes as an integral part of the result: what years) who after some attempts reaches the numerical result 0.5 although he does not add units “meters and steps”, he could have thought that not steps, because it does not correspond to the meter and that is how they are called: ”meter”) and therefore cannot be accompanied by a fractions of a meter, and that explains this type of response. They didn’t consider it important. This may mean that they have not understood the dilemma of which unit of measure to assign. As you have surely been working with the In the example shown, Michelangelo arrives at the numerical result 0.5 by half material,” such as the wooden rulers teachers use on the blackboard, which measure a possibly they did not want to face that dilemma and decided not to write anything, or else that of the algorithm (but the same happens with those who use the calculator) and faces the under construction and therefore cannot be properly coordinated. integers”, as discrete quantities (possibly representing a meter, ”concrete or In category 3 (N=24, 7.29% of the total), those students who During the interviews, some students comment that ”meters are Although it requires a more detailed analysis, it can be anticipated that these are notions Category 3. Correct numerical result but without reference units. You may have considered that it is a contradiction to write “0.5 meters”. decimal metric system, like the numeral system. Machine Translated by Google Image 8. Example of category 4 resolution. Image 7. Example of resolution located in category 3 attempt 44 in which it does write ”meters”, which indicates that it could have been a simple forgetfulness division 70 steps/35 meters (N=64, 19.45%); understood the problem statement In this example it can be seen that he identified the problem data, discarded result two meters, which also ruled out. Possibly he considered that it was not possible which did not specify the units. time correctly and initially operated with the 70/35 split, obtaining as take steps of that size and by means of another calculation, not represented graphically, arrived correctly chose the data and the appropriate algorithm, they obtain as a result 2 and the Category 4. Inversion of the data in the division (with reference units). The vast majority assign a unit of length (such as meters). to the result 0.5, this time without defining the reference units, unlike the first 94 In this category are grouped the results of the students who choose the Machine Translated by Google described in the analysis of the relationships depicted in Figure 3. What is the reason why by the study by Fischbein et al. (1985) show that indeed students The two possibilities are not mutually exclusive and it is necessary to deepen 35/70 as it would correspond according to the relational calculus by means of scalar operators through clinical interviews to confirm them. However, the results obtained Those who answer two meters is because they divided 70/35 instead of 2 steps per meter (uncommon) and get the correct result. that a person take steps of 2 meters; then possibly they thought of another alternative: reverse the divisor and dividend or change the interpretation of the result by this procedure, as in the example of Image 8, but they did not consider it feasible It is considered that there are at least two possibilities: 35/70? Some students who gave a correct answer (Category 1) earlier passed which one fifth of all students divide 70/35 instead of dividing 95 about the divider”. produce a graphical representation in the following order: write first left to right: the 35; then, to the right of it, they write the galley and at the end, inside it, the 70. The directionality of the alphabetic writing system ”interferes” with that of the • Another possible explanation is that they operate under the theorem-in-act “on division, the With the above it is represented graphically (the arrow indicates the division algorithm, so students write the division in the The larger number always takes the role of dividend while the smaller number, the directionality of writing) the statement ”thirty-five out of seventy” of and they write it in the order in which it is expressed orally and from left to right, order and directionality of alphabetic writing. That is, if they decide to divide 35/70 Machine Translated by Google didactic. It surely intervenes based on the relationships established between the conflict by adapting the text of the problem to its result. For example John Paul (12, 3), It is true that these answers can also be interpreted in terms of the contract conflict. However, there are those who do it and still maintain their result and solve the problem. Whoever accepts this result as correct generally does not evaluate the answers, but they could not be considered independent and exclusive. For example, Vergnaud’s perspective are called theorems and concepts-in-act. feasibility of taking two meter steps in the real world and therefore does not cause you any Other types of considerations would also be relevant to explain these of the following category, which together make up a 45 little more than a quarter of the They face new situations that put them to the test. These invariants are the ones that since 96 answers (26.35%). define its role in the graphical algorithm and therefore explain this set of responses and the students to develop invariants that continue to direct their activity until they operate under the tacit model of the characteristics of numbers in the operation to use types of problems with these characteristics that are the first approach to (See Image 9). teacher, students and the division, since during the teaching of the algorithm from primary school C (rural), who says ”He doesn’t walk, he hops and jumps two meters” Image 9. Modification of the text of the problem due to an incorrect result. Machine Translated by Google we could say that they did not understand the problem or that in that specific situation they did not 97 result 2 and that way you write it without needing a reference unit. It is necessary to highlight that only a quarter of the students are from those who perform one or more operations with the data of the problem, adding or not units procedures for its resolution. of measurement. Others decide to make some intuitive approximation of the size of the steps. proportional relationship and therefore its resolution procedures are oriented to answer. For example, Jaqueline (13, 11) from the urban high school, obtains as involved in this type of problem and therefore cannot generate they obtained and prefer not to write units or do not consider them as part of the difference is that they only give the value of the magnitude but without reference units (N=82, 25%) or simply did not understand. They could not establish that have faced various problematic situations that help them build the notions (N=23, 6.9%). They can mean that the students were not clear on the result The results of this category have the same characteristics as the previous one. The understood the relationship between the quantities expressed in the statement of the problem Students whose response was classified in this category may not have Category 5. Inversion of data in division (without reference units) In this category were grouped the results that make us infer that the students did not half are primary school students (65.8%). Category 6. Misunderstanding of the relationships between the data. They had the necessary schemes to deal with it adequately. Of that 25%, more Image 10. Example of category 5 resolution. Machine Translated by Google This category was divided into 5 subcategories, due to the characteristics of the What is expected of them when faced with a mathematical problem is that they perform an operation and give a results (See Table 10). answer, but since they are not clear when establishing the relationships between the data of the 6 a.m. Here the results were grouped that allow us to infer that the students 98 problem, then some choose to multiply them, others to add or subtract them and give Ernesto (11.9) from primary school A, gives us a typical example of this kind of a result to which some unit of measure is assigned (N=20, 24%). they assume that they must comply with the expectation of the situation and consider that what is resolution (See Image 11). Sub-categories 20 6 d 54 100 16 22 6 6 26 6 c Total 5 5 18 Primary % 6 6 b 28 4 17 Total 1 7 6 a 11 6 and 24 21 21 Secondary 82 16 12 Image 11. Prototypical resolution of Sub-category 6 a. Table 10. Distribution of the Sub-categories of Category 6 Machine Translated by Google 46 This is the case of Jaqueline (14.4), from an urban high school, who as a process of 6c. In this sub-category are grouped the results of the students who make an intuitive approximation of the size of the steps without apparently taking into account the data of the problem; or if they had been considered, they did not use them to operate arithmetically and they give answers based on an intuitive approximation using length units of the decimal metric system to express the size of the steps (N=17, 21%). units (N=21, 26%). units, allow us to infer that the allocation of units is one of the main solve applies division and multiplication to the data in the unassigned problem These data, together with those corresponding to the categories in which they do not add difficulties that students experience when solving a problem and therefore a Viviana (14, 6) from the urban high school, gives two result options without units of reference to the numerical result (See Image 12). mediates some written operation, apparently by approximation (See Image 13). important issue for teachers to consider. 99 6 b. Here the students do what the students in the previous category do, but do not add Image 12. Example of resolution of Sub-category 6 b. Image 13. Example of resolution of Sub-category 6 c. Machine Translated by Google students are very ”elementary”. 6 e. In this group were classified those answers that cannot be included in much interest because they show that the mathematical conceptualizations of these be small and then correct and decide to be large (See Image 14). Image 15). students, who represent 7% of this category and less than 1% of the population Laura (15, 4) from the Rural secondary school decides that the steps are small (See the previous ones and that show a frank lack of understanding of the problem. There are only 6 It is noteworthy that the responses of sub-categories 6 c and 6 d contradict in a way 6 d. Here were located the results of those who make the same approximation as 100 total. as a reference for their answers and they give answers such as ”small”, ”medium”, numbers given to obtain a result. In any case, they are responses from “normal” (N=18, 22%). These results are obtained in both primary and secondary. For example, Ángel (14.9), from the urban high school, first thinks that they should in the previous case but without specifying units of length of the metric system decimal flagrant the didactic contract, since at least they would be expected to use the values Image 15. Another example of resolution of Sub-category 6 d. Image 14. Example of resolution of Sub-category 6 d. Machine Translated by Google rejection of the activity. approximation of the number of steps and not of their measurements (See Image 16). It can also be answers given without reflection or as a sample of 101 Like José Alfredo (15.4), from the urban high school, who responds with a Image 16. Example of resolution of Sub-category 6 e. Machine Translated by Google IV.3 CONCLUSIONS OF THE PHASE RESULTS although they probably have constructed the notions involved, they still require the theory of conceptual fields, the construction of concepts does not occur from 102 recognized a proportional relationship but, due to problems with the units or with the reference, then the students who gave an answer from the second class (41%), consolidate and coordinate knowledge about the numbering system and about the construct the implied notions (for example, proportionality) and that, 47 as correct answers, which integrates the answers in which it can be inferred that indicate that the students did not understand the proportional relationships in the require mastery of the multiplication tables, whose memorization is essential, so a single situation, but through many and varied situations and in the long term; to the concepts and not isolated concepts as conceived by Vergnaud. In our study it is algorithm, they did not give an adequate answer and the third that includes the answers that algorithms. The first is not enough to give a correct answer; besides, At the same time, a situation always involves several concepts forming systems of If it is assumed that those who adequately solved the problem (34%) have complete results (with units), since its specification is not only they are precisely developing those notions. problem or were not sufficiently involved in its resolution. decimal numbers and the metric decimal system. Furthermore, they must take care to express their of a quarter of the population and the majority are primary school students, who Based on the analyzed results, three large classes can be identified in which succeeded in coordinating both the numerical calculation with the determination of the units of The responses of the third class may suggest that the students still lack which we can group the answers given by the students: the one that integrates the managed to construct the notions involved in the problematic situation and have also conventional but is an integral part of the solution. EXPERIMENTAL Machine Translated by Google 103 variation in the magnitudes of the problem, which did not generate significant differences in the irrelevant as a distractor is an element that causes greater difficulties in support in some aspects of the problem solving process, for example in characterization of the resolution procedures with the help of the calculator and without they could be explored further to find finer distinctions; without know the scope and limitations during problem solving. we coincided Although only the results of a first approximation are reported, but it could that they expressed to operate with the mobilized concepts. significant in the results obtained, at least statistically. However favored better results, if the criteria we used to operators, with the use and interpretation of the reference units and with the interactions between the student and the interviewer in testing the theorems and based on reasoning routes, procedures that students results. students to get an adequate representation of the problem, unlike the arithmetic calculations and verification of numerical results. But he. This was due to the fact that during the clinical interviews, topics arose that were However, only the statistical tests were applied to the data collected in the first with some positions that are in favor of its use, that is, that it can be a Regarding the hypotheses initially raised, the presence of a piece of data having carried out a methodological design that would allow reporting in greater detail the On the other hand, the differences between the results of the rural and urban localities We believe that it is a topic that should be further explored in greater depth to determine a correct result (correct numerical result and reference units). concepts-in-act identified. Exploring the domain of different content followed during problem solving and graphical and non-graphical representations On the other hand, the availability of the calculator did not generate differences We 48 differ in that it is a support in relation to the identification of the relationships between the results analysis. That is why we consider that it was not a resource that gave them priority, such as changes in meanings due to the Machine Translated by Google Mastery of mathematical tools. Regarding this issue and despite the between rural and urban, however it is possible that with another strategy rural and urban populations. different evaluations, but that does not mean that they do not reason as they have sometimes correct answer. to be confirmed or refuted in subsequent investigations to know if indeed these tools, mainly, is that difficulties arise and they fail to resolve Nor do they allow one to explore the existence of other theorems-in-act that may be mathematician than students from urban locations. That is, it is easier algorithms well mastered, mathematical notation well learned, both in the skills that would allow them to adequately solve the problem. Difficulties Finally, it becomes evident that there are differences in the systems of the problem; however, given the methodology used for this phase, the data does not results we maintain the hypothesis that students from rural locations can methodological differences can be found between the resolution procedures and the With all of the above we can conclude that most of our students do meant to suggest when interpreting the results of standardized tests, the 104 there is a way to deal with clearly different mathematical situations between phase of the field work, from which it is concluded that there were no differences the expected way the problems and can be the cause of the low scores in the determining resolution procedures that prevent students from reaching a resolution could assess their results based on their empirical feasibility, but this will take production and interpretation (writing and reading). Lacking mastery of representation and degree of consolidation of the mathematical concepts involved in allow us to confirm the nature of these relationships between representation systems. more easily use common sense when solving a problem they reason, that is, they do perform the pertinent relational calculations, they activate the schemas they arise when they lack the solid mathematical tools to operate. That is to say the mainly international. Machine Translated by Google resolution of the problem, as well as clinical interviews and analysis of the procedures 105 To deepen the above, direct observation is required during the that students do, which we expose in the following chapters. Machine Translated by Google symbolic representations and mathematical conceptualization in solving problems Finally, from this microgenetic analysis, axes of secondary solved the problem of steps. The records obtained allowed us depth in clinical interviews according to our object of study, namely, the relationship of problems. Andrea was willing to work in depth on each of them. In the first place, the way in which 329 primary school students and graphic representations used, interpretations of the problem and knowledge microgenetically the case of Andrea and document it in this chapter to account for analysis to be explored in the rest of the clinical interviews. We also highlight 106 classify their answers and identify the diversity of resolution procedures, of Subsequently, of the 30 clinical interviews carried out, it was chosen to analyze particular topics that were of didactic interest. difficulties encountered by students. mathematics as well as the 49 co-construction of knowledge in a specific situation. mathematicians mobilized to face the situation as well as to identify the main of the complexity of the procedures, both of the resolution of a problem sixth grade student from an urban school. We consider it pertinent ”experimental phase”, we were able to identify themes that should be explored more themes that appeared in an isolated way in the rest of the students, in addition to the fact that describe the methodological path followed to reach this point. This chapter reports the microgenetic analysis of the clinical interview with Andrea, a With the results obtained in this stage of the investigation, which we call This case was chosen because in the preliminary review we noted that it covered many CHAPTER V. Results of the microgenetic analysis Machine Translated by Google V.1 THE CASE OF ANDREA interviewer not only collected information for research purposes, but also Situated microgenesis approach as an interview analysis tool. The interview is analyzed in fragments that correspond to the application of one or so that Andrea could adequately solve the problems raised. He assumed the role of ”teacher”, seeking to propose situations that favored the For this reason, the methodological and analytical principles of the as well as resolution procedures. interviewer is guided by the schemes that are activated by the situation faced only a data collection instrument, the interview became a space 107 various procedures. We assume that the activity of both the student and the modification of those theorems by other more productive ones. Therefore, instead of being procedure, but will be used to describe something that we consider pertinent new reflections that would allow, firstly, to recognize them and, secondly, (both one and the other). The components of the scheme will not be described in each of didactic work in which the errors detected were used to promote student actions during the resolution activity. The notion of schema that During the interview, theorems-in-act were identified that generated obstacles written production (Dolz, Gagnon, and Vuillet, 2011). Vergnaud proposes in his theory enables us to explain both the concepts mobilized The theory of conceptual fields allows us to analyze in sufficient detail the highlight. overcome them, in a similar way to what Joaquim Dolz proposes for the teaching of Machine Translated by Google Image 17. Andrea’s productions in the experimental phase. Andrea canonically represented the written division algorithm and they had at their disposal a calculator that they were free to use. Despite this, the multiplication. solved correctly. Furthermore, it is interesting that he has repeated the same problem group gave an answer considered correct. In your group, everyone two divisions have the operators interchanged (70/35 and 35/70) and then the Image 17 shows the result and the graphical operations it performed. operation with the same result, because generally when students perform He obtained it, apparently, through the V.1.1 DESCRIPTION OF THE CASE 108 The answer it gives is .5 meters6 . a public school in the capital of the State of Veracruz. In addition, it can be seen that he carried out a verification by means of a In the first phase of the study, she was one of the students who in the application Andrea (11.3), at the time of the interview, was in the last bimester of sixth grade at division algorithm, an operation he performed twice and with the same result. 6 Transcription code: 50 between square brackets the expressions and productions of the interviewer, except those of the student. Written productions are underlined. Some clarifications or comments are in parentheses and some key expressions in the analysis are highlighted in bold. When a phrase or words were not heard or understood, we put the number and F or P respectively in parentheses for a phrase, for example (1F) or 3 words (3P). We emphasize with bold what we consider important to highlight. Machine Translated by Google V.1.2 MICROANALYSIS of his graphic productions. It lasted 59 minutes. Andrea showed up with the This second phase, in turn, was segmented according to sub-goals or sub-objectives due to During the interview, Andrea is placed in an evaluation situation in a and gestures during problem solving and identify order and directionality restlessness of not being left with doubts and, realizing that in reality he did not master to test those hypotheses and, as far as possible, try to modify them. She solves problems and is convinced of her results. as a teacher, so she assumed the role of student. The interview took place in a The interview was prolonged, but she was constantly monitored for fatigue. the difficulties encountered, the procedures chosen or the interventions of the 109 school context with the figure of an interlocutor to whom she surely attributed the role some basic questions, he wanted to understand and learn them. It is for this reason that the interviewer. administrative staff and talked to each other, which at times made it difficult to listen clearly. The student chooses the result that he considers most appropriate. Despite having his For the analysis of the interview, it is divided into two phases. The first consists of the small teachers’ room where two teachers filled out some forms Andrea, throughout the interview, appears very confident and willing to The interview was videotaped with the intention of recording their verbal expressions. Andrea’s hypothesis and the approach of new problems by the interviewer respond to questions and problems raised. Verbalize what you think while available a calculator, performed written operations and developed them. Andrea’s expressions were clear. resolution of the problem and its verification and the second in the exploration of the Machine Translated by Google how long is each step [aha] (divide 70/35= 2) and gives two [and gives, two. how fast, we consider the assumption of a didactic contract (Brousseau, 1997). meanings. So , should I divide 35 meters by 70?... so that it gives me the result of you are very fast... And two, what will it be? Write your answer] two meters [two could commit to adequately solving the problem raised, which resolution, if necessary, and to the extent possible, build new distance of 35 meters. He expresses orally, with some doubt, that he can obtain the Steps? [As from where to where] (Indicates an approximate distance of 2 meters) To achieve the goal of finding the average size of each step, she 110 Andrea reads the problem and understands that Hector walks 70 steps and covers a meters?] Yes [Ok, what do you think of your result?] Well, how big are the expresses orally that he plans to divide 35 meters between 70 steps, with some doubt, inferred different from the one stated: 70/35. It can be assumed that Andrea recognizes a problematic situation that must be result “dividing 35 by 70”; however, it does graphically represent a division [So they are very big, but that gave] aha. The interview 51 is aimed at exploring the knowledge that Andrea is capable of Steps? [What did you understand?] I say that he walks 35 meters in 70 steps, Therefore, she as a student could be considered in an evaluation exercise. In doing so, mobilize to identify these problems, reformulate its procedure of Reading the problem and initial resolution Hector walks 35 meters and takes 70 steps. On average, how big are your resolve by finding yourself in a school context, and as already said, with a teacher and V.1.2.1 FIRST PHASE Machine Translated by Google express graphically and orally as two meters; In addition, he recognizes that they are very large Division other than the one that he enunciated orally. Carry out the algorithm and get determine the result. It is considered that it is not only about the passage from the oral to the written, ability to switch from one register to another between representation systems. But, operator function proportional (:2) to the unit value of a step to find its or not, and neither does it autonomously recognize the difference between its verbal expression and the division, graphically represented the oral expression of the operation using the rules theoretical), it is possible to find the value of a step through two operators, applying the may be used to in the classroom, she concludes the process of the result by means of the scalar operator (70 times less) without dimension. In the oral expression ”should I divide 35 meters by 70?... for him to give me the answer that she considers as the solution to the problem: 2 meters. The change between the important. the steps. quotient 2 without specifying reference units, which at the request of the interviewer she but that the graphical representation has conceptual implications both of the algorithm of What specifically would such an ability consist of? 111 written in the division, nor that the order of the “data” in the division is important to of interrogative intonation. During the activity graph 70/35; is a of the alphabetic writing system. In terms of Duval (2006), this would imply a lack scalar operator (70 times less) to the known measure, in this case the 35 meters or the resolution. She does not consider herself the possibility of checking if the result is correct However, instead of graphically representing the operation by means of a Oral expression and written representation of the division have conceptual implications. As can be seen in the schema of relational calculations (See Chapter Possibly, due to the situation of interaction and the level of demand to which division as the proportional relationships at stake. result of how long each step is” adequately expresses the operation to find Andrea autonomously complies with the objective (of the contract) of giving a Machine Translated by Google Figure 8. Scheme of relationships by scalars. we would need a place that was 35 meters and... we would measure step by step obtained with the real feasibility of taking two-meter steps, but this is not enough [How could we do if we wanted to check that your result is correct] step... it could be [It could be] or we add it up [do we do it?] yes, 6 meters the same Andrea correctly solves the algorithm and manages to relate the result Check Request 112 to deduce that it is wrong. 3 steps, right? And so... (He rotates his hand as a gesture of iteration, of repetition) with correct. She proposes two alternatives, both valid. For the first, comment that corresponding measurement in meters. The interviewer asks if there is any way to check if your result is correct. find 52 the value of the ratio of the proportional function (2) and not the measure of a step. the second is to “add it up”. Andrea divides 70 steps by 35 meters, which in the scheme would imply ”We would need a place that was 35 meters and... we would go measuring step by step”; Machine Translated by Google Image 18. Correspondence table. (See Image 18). The first alternative refers to a specific plane of representation and the second of the activity by means of the graphic records in a correspondence table board). practices and is asked to do the second (although it must be admitted that it would not have been 12 m meters - 6 steps refers to an arithmetic plane; the first check is discarded for reasons 6 m meters - 3 steps so then I multiply it From this moment on, Andrea’s actions are directed to another the table of two [Let’s see, do it. It is a way to check it and it is very good and 48 m meters - equal to 24 steps bad idea to go to the schoolyard and put it into practice). 24m meters - equal to 12 steps completely convinced and it is already verified] yes [if we do it it has to come out of 35 meters. To achieve this, she structures a strategy that allows her to take control the same] uh huh [you would be too lazy to do it] no [do we do it?] (Complete the idea] and 35 is double 70 and since they are two steps [then you are objective: to determine if taking 70 steps of two meters is enough to cover a distance 113 Machine Translated by Google steps down the line; in the same way it does it with the 48 meters and the this is almost done (he laughs as he points to the twelve meters and then the oh…no, or yes? No, because here you have to take up to 70 steps (points to the column of between the two columns: in the first it represents the distances in meters, with a series 114 I haven’t already passed it. Oh no, I haven’t gone too far. Here until it hits 70 (points to the column and I already spent even more [aha]. allows you to identify the next number in each of the columns, but at the same time (56)] because it is double of... (Realizes that there is a mistake) then they would be 48) should be here (it makes two small marks, one in the column of 384-192 steps... (Looks at his correspondence table) I’ve already passed [have you already that the number of steps corresponding to 6 meters is 3. table, relying on the characteristics of the graphic representation that somehow 48 steps) [(I point to the meter column) and here you add 6, 12, then...] twelve steps from the line below, then point to 24 meters and then 24 the steps). [Follow him]. that starts with 6 meters and that is doubling at each level; in the other column represents of the steps). [Let’s see, follow him]... oh no, I already passed, yes I already passed [why?] 56 m meters - equal to 48 steps As seen in Image 18, Andrea identifies and reproduces a relationship time loses control over the objective of the procedure and the goal to be achieved. here 96. [96?] Yeah and see... [How far do you have to go?] Until... the... ah meters between 24 and 48, and another in the column of steps, between 12 and 24) Andrea finds regularities during the construction procedure of the They confirm the appropriateness of your procedure. Generates a calculation rule that 24 because it is twice 12 [and here (48)] 48 because it is twice 24 [and here? 192 - 96 steps did you pass?] yes because it is 35 meters (indicate the number in the meter column the steps and, since he considers the steps to be 2 meters, calculates correctly Machine Translated by Google 115 mark 53 graphically. purpose of your procedure. However, it is from the written record that she can add 12 + 5 = 17) [17 what is it?] 17 steps and one meter left over. [But tell me 17 steps of 2 meters and you say that there is 1 meter left over] uh-huh [and this is the result of measures. The result he arrives at is very original because 35 meters correspond to 24 meters out of 35, so we still have... 11 meters to go. But? [11 meters for 35] uh-huh eleven [ah, 11, I’m missing 11 for 35, equals...] to 5 steps and one meter left over [and In this sequence of actions, he systematically varies a quantity in it would be 15 (write 15 below the 12) yes, right? [I did not understand you] well we are here he advances 24 meters it’s because he took 12 steps, we’re going well up to there] uh-huh [then you said, why did you choose 6?] times two (refers to 3 (steps) times 2 equals 6) (nods) [and is this a way to check?] yes [are you convinced?] yes Concludes the series with a relationship of 35 meters is equal to ”17 steps and Let’s see, then, well, we already have 12 steps (12) and we are missing 6 (he means that, redirect the activity to the initial goal. Locate an arrival point in each column and (point to the sum) what are you doing? 17 steps, what does it correspond to?] It would be the check if you can take steps of 2 meters] uh-huh [you say that in order not to have 17.5 steps of two meters each, but to avoid decimal numbers, which makes [uh-huh] we are 11 meters short, we already have 12 steps, we are 6 plus 5 more (write the The interviewer is required to intervene for her to regain control and the this 12 what is] 12 plus 5 steps is equal to 17 [it means that 35 meters is equal to proportion to the other, which means that it identifies a proportional relationship between both (make a mark in the meter column below the number 24); we have (24) is missing 15 for 35, here are the 15, I point to the second result] no, [100%?] mmm yeah. “There is one meter left.” as 12 steps and 24 meters correspond, there are 6 meters left to reach 30) and that... [Have you already screwed up?] yes [don’t worry, we’ll understand him (I point to 6 m) [ok, if he takes 3 steps he walks 6 meters, if he walks 12 meters he walks 6 steps] (nods) [yes to go to a distance of 35 meters and walk it we can do this (table)] Machine Translated by Google ... [do we?] yes, 6 meters equals 3 steps right? And so... (turns his hand as a gesture of iteration, of repetition7 ) with the table of two. if he advances 12 meters he takes 6 steps] (nods). 116 wanted (35 or 70). However, he applied the rule systematically in both columns, relationship. He expresses it recurrently and through different signifiers: • two (refers to the fact that 3 steps times 2 equals 6) [ok, if he takes 3 steps he covers 6 meters, and applying “multiplication by two”, it would not arrive at either of the two numbers the table and cleverly and ingeniously solved the series finale. She considers completely convinced and it is already proven] yes. The conclusion you reach seems acceptable to you, but it does not correspond to the • identified certain arithmetic regularities based on the distribution of numbers in ... and 35 is double 70 and since there are two steps [then you are data of the problem, since Héctor walks 35 meters taking 70 steps and not 17, which meters per step is correct. is to keep the 17 steps and the half step, which must measure one meter, he prefers to leave it • Correspondence table. wrong way, which was an effective way of checking that your result of 2 • • The difficulties of this procedure are related to the 54 magnitudes that it identified from the beginning and that the result obtained in the division coincides with this ... [Don’t worry, we’ll understand (I point to 6 m) why did you choose 6? ] initials you chose to build the correspondence table; He did not anticipate that with them, as residue. It can be inferred that Andrea is focused on the relationship between the two magnitudes ... [and here (48)] 48 because it is twice 24. 7 Note that the gesture of turning the hand is also a signifier, with which we emphasize our main thesis, referring to the relationship between mathematical conceptualizations and representation systems. It is not useless to remember that Piaget identified the origin of the first semiotic systems with the internalization of action schemes. Vygotsky also emphasized the internalization of gestures as the origin of representation systems. Machine Translated by Google interviewer wants you to realize the mistake and try a new strategy to is observable for her (given the sequence of reasoning, the starting data ÿ2 is the [What does the problem say?] Hector walks 35 meters and takes 70 steps on average, because it allows you to observe the relationships and therefore attribute the lack of I think it gives 50... no, yes it can... because it would be centimeters (add cm to the with the problem data. She correctly reads the data and identifies that it is different from her Andrea finds the error to be in the split after a review, which 350 centimeters (divide by 70 you get 50 and cross out the division) but it is countersuggestion (70) so since they are 35 meters I thought they were two meters each meters] 17? No... yes [but here in the problem does it say how much?] seventy [and here very convinced] uh-huh [later we wanted to check but you’re already doubting] uh-huh [for [let’s see] (looks at the sheet for a moment) you couldn’t because there are 70 steps (points to the find the correct result. Then begins another sequence of actions aimed at resultÿ and the difficulties encountered due to the random start ÿthe relationship 3-6ÿ). He how big are your steps? [He says that he walks 35 meters and how many steps does he take?] correspondence to the result of the division and not to the verification procedure. 117 result but keep thinking about the two-to-one relationship between 70 and 35. it means a loss of control of the activity (”he balls up”); it is something that is not it may mean that the verification procedure seems more “transparent” to you wrong... [have you had enough?, why do you say that this is not (I point to the division)] why not She is asked some questions so that she can identify that her result does not match and I already divided it (he points to the 70/35 division) or maybe the division is wrong. where would you like to start] by checking it [which] the two (division quotient) data in the text of the problem) between 35 meters (points to the data) and each meter are… to achieve these new partial objectives. It would be that instead of 17 steps it would be 17... [But how many steps does he take to advance 35 how many did he give?] 17 but here it is easy because this (35) is twice as much as this [Well, we already have several problems here, one, you did the division and you were Machine Translated by Google performance during the activity, is generally circumstantial and therefore temporary and but for a time it causes him some difficulties. problem text). (2011, p. 33). The first, we will use it to describe a fault product of the local. On the other hand, the error is a systematic 55 failure indicating the process of loses 3500 (three thousand five hundred). Later he realizes the error and corrects it, because 350 cm is fine because they are 35 meters (point to the data of 35 meters in the it was not possible; Then, solve the difficulty of making a division with a dividend less than the This wrong calculation does not mean that she does not know how to multiply by multiples of At first he considered the possibility of dividing 35/70 but thought that construction of mobilized knowledge. 118 350 cm and not 3500 cm. This strategy is very appropriate, relevant and simple. Without quotient) and would be fifty point meters (add a decimal point to the left in which it could have influenced that, in its conversion logic, it considers that each meter divisor through the erroneous conversion of meters to centimeters, since it affirms that they are 10 or that does not dominate the conversion; It is perhaps a mistake when mentally calculating meters?] uh huh , but I don’t think that... there I have a question [what] I don’t know why, but we consider a mistake to differentiate it from the error as proposed by Dolz et al. centimeters, keeping in the result the lexical base of one hundred (three hundred), which is I feel that it is wrong [yes?, what do you feel, let’s see?] that the division is wrong of the quotient and write one m to the right of cm) [¿50 centimeters is equal to 0.50 However, he does an incorrect mental calculation by multiplying 35 by 100 to get 350. it is 100 centimeters; and if it is 35 meters, the result would be three hundred and fifty Image 19. Division that Andrea considers to be wrong. Machine Translated by Google Once again, the interviewer seeks to explore whether she manages to sustain that result. ball up, 50 cm times four (write 4) [why times 4?] 4 times 50 is the same result may be wrong by looking at the division quotient. After doubting, think to the problem, the procedure by which he arrives at it is not clear to Andrea. convinced that this is the correct answer. In this segment we can see [How could we do to verify it] I am going to write it here so that it does not He performs relational calculations based on writing, that is, he deduces that his a decimal point and the abbreviation for centimeters. However, when seeking to specify that they are conversion and manipulation of the decimal point. 119 that it is possible that the result is 50 because it is about centimeters and then add clearly the interconnection between the empirical feasibility of the result, the millimeters. When rewriting, correct and only leave 50 cm. If he had done the 350/70 division correctly, he should have obtained as a result The following sequence of actions is intended to check if 50 cm corresponds to 50 centimeters, actually represents graphically 0.50 centimeters, that is, 5 new check partial and gets 50. However she initially says she ”feels” wrong, but Although the final result is correct, since it responds as expected the first check. Start the series with “4 times 50 equals 200.” more for the result than for the algorithm’s resolution procedure. 5. But not fully mastering the algorithm, you arbitrarily add a zero to the quotient the right answer. Andrea again makes a table of correspondences as in Image 20. Complement the quotient with units of measurement. Machine Translated by Google meters (mark a decimal point to get 35.0). [Let’s see, explain this to me, 200 cm is equal to 4 steps] because 50 plus 50 (count 2 Well yes, but that’s how I go… [Okay, 4 what would it be] four… steps? (add a pa (draw a horizontal 56 line under the quantities and add) and give 350 and with your fingers) there are two steps, there are 100, then another two are 200 and here there are 3, 4) then it would only be another 3 steps equal to 150 cm so it is added here it is 7 p.m. Steps. (Write 7p in the left column.) 120 are 150 and here (the result) would be 350 centimeters (add cm) which would be 35 to 200 (write 4= 200 cm) [I didn’t understand you, why 4 times? Could it have been 6?] Image 21. Relationship between the algorithm and the correspondence table. Image 22. Sum of the components of a correspondence table. Machine Translated by Google Initial error identification convert it to 3500) [kind of works itself out, right?] yeah. She identifies with only the interlocutor’s question and doubt that 350 centimeters that the result is correct even though Andrea thinks it is. initial: that 35 meters is equivalent to 3500 centimeters and not 350 cm, as she considered. calculation. You are asked to check again, the interviewer considers that now The following intervention by the interviewer seeks Andrea to reflect on the error equals 3.5 meters and easily corrects, confirming that it was a mistake 350 centimeters [a little? How do you know that?] Because meters have 100 Its verification has two characteristics: it starts with an error, since [Tell me why you put 350 (in the division)] because it is 35 meters and it is equivalent to everything will become clearer for her. of correspondences with the data of the problem: 7 steps and 350 centimeters is similar to meters to be 350, then it would be another zero (add a zero to the dividend to 121 70 steps and 35 meters. Again the procedure does not allow a clear demonstration Consider that 35 percent is equal to 350; establishes a relation of the result of your table centimeters... [Aha] oh no... then it would be three point fifty, three point five Image 23. Division 3500 cm by 70. [Look, I would like you not to worry, we are testing the options] uh-huh [do you want try it like this?] yes [try it, do it here if you want] (does a division 3500/70 =50 does not write Machine Translated by Google residues, only the quotient) gives me 50 [does it give you 50?] yes, no... to 500 (doubt) [What did you write here? (3500/70)] Seventy out of 3500. Image 24. Obtains 50 or 500 as a quotient. of the division is done “by columns”, which means that the dividend is of one of the other three operations of elementary arithmetic. In the second part of Paraphrasing Martínez (1997, P. 71) the procedure for the usual algorithm breaks down, in this case, into units of thousands, hundreds, tens and units. HE usual division algorithm. The same does not happen if you use the calculator or if you try depth this relationship and seeks to problematize their distinction. that the relative value of each one be considered. this interview, once the resolution of the problem is finished, the requires dividing each of these elements separately or joining two or more figures without Once Andrea corrects the conversion from meters to centimeters and writes the division 122 About the division algorithm In the division Andrea wrote: problem posed, is now faced with the resolution of the algorithm. This particular relationship between oral language and writing only occurs with the corresponding to the operation that you plan to carry out, and that it is adequate to resolve the problem. Machine Translated by Google Image 25. Division 3500/70. steps of the algorithm, it is absurd to seek to distribute the zero and find that it touches zero Let’s 57 analyze Andrea’s procedure: forming 350 tens. 350 tens can be distributed among 70. Touch 5; this 5 This last step is counterintuitive, since if you want to be systematic in the times. This step caused difficulties for some students who faced this the logic of the numbering system can deduce this. Hundreds cannot be divided between 70 either, so they are ”joined” with the tens, Since there is nothing left over, zero is written as the remainder; the following figure is “lowered”, which in remain and may be related to the mistake Andrea made when dividing 350/70 and means 5 tens and must be written above the dividing point in the tens place. problem because it is at this point where they do not know what to do with the zeros that 123 distribute the ”zero” among the 70, which touches 0, which is written in the dividend in the An alternative way would be to reason it like this: “We divide the 350 tens among 70, this case is a zero. If we wanted to continue with the procedure we would have to look for get the result 50 instead of 5. 35 zero. units, the quotient is complemented by writing zero units”. but only dominating 70; Since it cannot be done, it has to be ”joined” with the hundreds, forming 35 hundreds8 . First, you want to divide 3, which actually means 3 thousand units, by units position. Finally, the remainder is written, which, in this case, is also what touches 5 tens; there is no more to distribute, the result is 5 tens, that is, 50 8 In the terminology used in a system to teach algorithms called ”The Arithmetic Table” (The Arithmetic Flea in its digital version, 2003) there was talk of ”changes” from thousands to hundreds, etc. See: http://www.uv.mx/cpue/coleccion/n_2526/publjor3.htm Machine Translated by Google (as a discrete quantity) cannot be divided by 70 because it contravenes a rule 124 it would be 50 (write a zero in the quotient) [good] and now 50 [what is that 50, Oral level: ”I don’t think 3 fits in 70”, which may mean that 3 for her fundamental of the division that is that each one receives the same; if he distributes the three As already mentioned, it is counterintuitive to continue with the same allocation procedure; quotient) because it goes 5 times and zero is left over and we lower the zero and it does not give anything, (add a c before the m). would be 35” which arithmetically means that 3 thousand units are converted to what does it mean?] 50 meters per step (add one m), no, 50 centimeters per step There will be 67 who don’t get anything. Then he expresses ”so we’ll see if it’s for the second, Evidently, Andrea dominates, at the level of operative invariants, a series of [How do you solve a division like that?] I don’t think the 3 will fit in the 3 who cannot divide 35 by 70 and takes the following figure, which would mean converting the hundreds and add to the existing 5 hundreds resulting in 35 hundreds. He realizes it fits, but it can’t be added... then we’ll see if it works for the second, it would be 35 the procedure mentioned above, but again express it in an inverted way to zero left over The next step is to lower the next number, which in this case is a zero. As but it does not work either because it is half of 70 so it would be 350 and it would be 5 (in the [that the 3 does not fit in the 3?] no, in the 70 [that the 3 does not fit in the 70?] well, yes knowledge of both division and the number system; for example, use 35 hundreds to tens forming 350 tens. He does accept that, and deduces that it is 5 and Image 26. 3500/70= 50 cm. Machine Translated by Google centimeters (add cm to the 58 multiplication result) and nothing is left over. In terms of Saada-Robert and Balslev (in press), the interviewer seeks that space of if the result is correct. It makes him see that the result obtained is the same as that obtained what?] let’s see... (Multiply 50*70=3500) no, yes it gives [yes it gives?] yes, because they are Define the procedure that most convinces you Then it self-corrects and concludes that it is centimeters. You are also required to check You can check the result by doing a multiplication. division. Before performing the multiplication, anticipate what the result should be, but 125 in a different division. She is wanted to anticipate what she will do and she mentions that To achieve the goal of checking, recognize the inverse operation to the [well now let’s check it] aha [how can we know what that is] she solves it apparently without difficulty, expresses orally ”we lower the zero and it doesn’t give surprised when she realizes that 50*70 does indeed equal 3500. Finally, [Very good; Well, he already gave us the same thing that he had given you here, right? 350/70= 50] uh-huh through some kind of relational calculus, you infer that you won’t get it. It shows It is necessary that the interviewer asks you to specify the meaning of the quotient 35 [let’s see?] no, 3500 because they are centimeters. But it doesn’t give, I don’t think it will give [why have residues and are part of the result; expresses that nothing is left over. found. First think in meters, perhaps because of the original problem statement. nothing, it would be 50”. multiplying? [What would you multiply?] 50 by 70 [how much should it give?] should give Andrea knows that in the division, unlike in the other three operations, she can Image 27. Check 50*70= 3500. Machine Translated by Google seems more appropriate. the interviewer’s meanings with Andrea’s. problem) [Point five what?] Meters (add an m next to the 5) [meters, why [Do you know a tape measure?] Yes [where would the answer be?] look in the 126 division and the multiplication that proves it) [Yes?] Yes [What would be the numerical representation and the concrete plane is asked to mark on a tape measure its Mark correctly on the tape measure the point that represents the measurement of the two?] this one that went out to two (points to the first division (70/35=2 m) and this verification procedure by means of the correspondence table. Although it was expected that she would directly choose the latter procedure, Andrea where point five meters would be (I point to the result he wrote)] here? (points to I saw… I just remembered that I did it last time and it also gave me this [So which of everything you did convinces you the most] I am most convinced by these The interviewer asks you to review your results and choose the one that best suits you. if you were using 50 and now…] because they are centimeters (point to the last few far left (as other children have done, and select 5 centimeters) answer to the question?] point five (write 0.5 next to the question of the interaction to determine if in the work done so far there are coincidences between result. passed. Furthermore, the notion of equivalence operates correctly by mentioning the term and (3500/70=50 cm) but I think this one convinces me more (he makes a mark next to To determine that Andrea establishes an adequate relationship between the plane of the same place) [same?] the same, because it is the equivalence [how did you see it?] result (points to 0.5m) I just remembered. two (point to the correspondence 59 table and the last division (3500/70) [what operations) so I changed it to meters. considers that the first one also convinces him, possibly because of the clarity of the ah, it’s centimeters right? So it would be here (correctly points to 50 cm) [and in Machine Translated by Google [What division would you have to do on the calculator...if you had to do a 127 that helped you because: what you “write” or type into the calculator, as you do with the usual written division. operation, which one would you do?] It would be 70 out of 35 because I made a mistake here (points to The application of this problem was solved with the help of a calculator and considers correspondences) and if I had it wrong, then I quickly saw the result and nothing more do you know which one goes in and which one goes out?] because we would have… the…. what… if it would be With her I was not making balls with the answers (points to the table of 70/35=2) 70 goes outside and 35 goes inside and that’s why it went wrong [how The interviewer regains control, suggests solving the problem with the pointing to the same place for different signifiers 50 cm and 0.5m. counting 35 steps, it would be the other way around. So it would be 70 steps on centimeters posted the results... thus (points to 70/35=2) it would be the 35 meters (points to the dividend)… we would be From your comment on the use of the calculator, we explored the way to intention to confirm if it maintains the correspondence between what is expressed verbally and 28). “write” the same algorithm on that device. She mentions that in the group phase of Solve using calculator calculator, but first he asks him to verbally express what he will do on it, this with the (points to 70 and 35 while enunciating it from left to right. See Image Image 28. Say 70 divided by 35 and write 35/70. Machine Translated by Google conventional written division, says that on the calculator he will divide 70/35 and points to the the data in the division, you know that changing them will get a different result. She says theorem-in-act: the distance always goes inside the house. From this invariant [okay, write it down (I pass you the calculator)] (type 35 / 70 = ) equals point five that must be problematized and therefore analyzed. Because of the difficulties they experience false even though for her they are true (Vergnaud, 2009). would you dictate] 35 divided by 70 [ok, here what division did you make (I point 3500/70] seventy presents and can get a correct result. identification of invariants in the interaction process, also builds theorems between seventy [What is the division you would make] this (mark with a circle 35/70) [I’m going to lend you the calculator and you’re going to do the division, okay?] Uh huh [what are you going to In this fragment it can be seen that Andrea actually “writes” in the of children who, like Andrea, do not establish the distinction between oral expression and 70/35 division, also explicitly mentions ”70 goes outside and 35 goes inside”. That’s why it ”went wrong”. Also for the first time he expresses verbally and in a surgery is that you will face the following situations, causing you that, in some [aha, so it’s very good, right?] yes [because you work very well] yes (laughs, he writes 128 In the following sequences of activities we can identify the genesis of a In this part of the interview, Andrea already establishes a difference in the order of between three thousand five hundred [and here what division did you make? (70/35)] 70 out of 35 Inversion in the graphical notation of the 60 division algorithm is a component en-acto that allow you to interact with the situations faced, but that are also [if you were to tell a child write this division (I point to the same 35/70) how calculator in the order in which it is expressed verbally. This data confirms that many written representation of the division, with the use of the calculator this problem is not Despite these significant transformations of their knowledge, from the Sometimes I can’t find the right answers. write in the division, what are you going to write here] here would be thirty-five your name on the sheet) Machine Translated by Google V.1.2.2 SECOND PART OF THE INTERVIEW First theorem-in-act. In the division the distance goes inside (of the house) and problem you solved and the interactions with the interviewer allowed you to arrive at this the best way the work undertaken and his desire to learn, he was raised a about these distinctions. others outside... This is the construction he made during the first part of the interview. He Due to the interest that Andrea showed in the activity, the effort made to make with the interviewer, will construct new explanations related to the issue of the order of I don’t know where to put the data in the slice, but it has happened to me in conclusion because initially he divided the steps between the meters. It is important to highlight voiced by Andrea; otherwise they might have remained implicit and therefore series of problems based on the ideas that he was formulating so that, in interaction [From the division, what is the...? What is the hardest for you?] I have a hard time sometimes that it is through the interviewer’s specific questions that these ideas are Andrea expresses some ideas that are problematized by the researcher and goes students, it is a content that probably has not been reflected enough in write outside?] because it would be the distance… because if it is distance the the data in the division. rarely [if that is difficult for you, how do you decide what to write inside and what 129 division and the significance of the graphical representations in the algorithm. The student is given a series of problems that allow them to reflect distance that you already have complete would be inside. the school. It requires a detailed analysis of the situations where a reformulating until he manages to recognize that he must reflect on some issues. problem would be the distance inside and the steps or whatever outside, the Machine Translated by Google Image 29. Conventional writing of the division. What can you think of?] An ordinary child can be one hundred and ninety three meters conventional and general to various situations. [Let’s see, let’s do some exercises] An example? [For example of distance in a race 193 m but they are divided between fifty-eight stations 58 would remain for a long period until they could be replaced by other more From knowing this idea, the interviewer tries to invent some situations At the end write down the divisor. See Image 39) [here is the calculator] (does this Countersuggestions to your hypotheses so it would be 193/58 (write the dividend first, then draw the galley and determine the order of the data in the division, that, when changing the order, the result Therefore, they would have generated unproductive rules of action in the situations that most each station would be] three point thirty-two meters. problems where Andrea, on her own, recognizes that it is important operation on the calculator and write the result it gives you) 3.327 [then determined by 61 the characteristics of the problem situations in which therefore it will require a new, more general construction. 130 I could eventually put them to the test. Surely some of the following ideas ahead could face. The modification, sooner or later, would be it is also different; to realize that the distance will not always be the dividend and Machine Translated by Google meaning of the result. punto algo y cacho [with the calculator] (carry out the operation and write down the result division starting with the dividend, then makes the galley and at the end the divisor, that is, from point thirty-two meters. On previous occasions it was necessary to ask him the In the following intervention, we try to show you that by changing the order of the divisor, then the galley and finally the 193 representing 58/193) would give me It is understood that you must find the distance between each station. Second, write the division: it no longer establishes that relationship with oral language; has been disassociated for this case [What would happen if you had done it the other way around?] It would give me another result that was 0.30 m.) is point thirty [point thirty meters, it is very different from this one (points to the 131 right to left. This represents an important change in the way of writing the data in the algorithm also changes the meaning of the result. operation 193/58 and 58/193. See Image 30)]. As mentioned, this is not a problem for students but, given the In this problem invented by Andrea, several points can be observed backwards, don’t you get the size of each station?] No (shakes her head) [What specific. Third, type the data into the calculator in the proper way. wrong [would it be wrong?, how could we know? So if you had done it initially mentioned, but from a different scope than Hector and the size of interpret the result as a distance magnitude according to the problem: three between fifty and eight meters [let’s see, try what comes out?] write 58 as your steps. It is now a race in which there are seasons. Although he doesn’t mention it, interesting to analyze: first of all, it creates a problem in the terms that previous change, for the writing in the calculator the order was not reversed. Finally, comes out?] comes out (thinks for a moment) if it were… one hundred and ninety-three seasons Machine Translated by Google Image 30. Inverts only the numerals of the division but not the units. what, but you know It also anticipates very well a decimal number as a quotient. 132 division, Andrea keeps the units in their original position: the meters inside the inverting the data the result will be “wrong”. There are no elements to explain why There is a difference between the meanings of the interviewer and Andrea regarding the is correct) or would be 30 centimeters (so next to the quotient add = 30 cm. stations instead of subways, it’s out of reach. By changing the data in the will divide among 193 stations. He constructed this rule to be consistent with his theorem that identifies that if you divide meters you will get meters and if you divide stations you will get dividend and seasons outside. Now instead of 193 meters it has 58 meters that content that at that time is trying to problematize. While the interviewer searches distance as dividend. This idea will remain until the end of the interview, where in this case meters or centimeters. The following intervention seeks to focus your attention en-acto, ”the distance goes inside the little house”; change the magnitudes but leave the seasons, Andrea only 62 considers as a possibility a quotient of units of length, interviewer and Andrea), because while the interviewer wanted her to realize Andrea interprets the result as 0.30 meters; however, it is clear that [How do you know it’s meters?] In meters because I divided it into meters (which realize that reversing the order of the data in the division would result in In this case, we can mention that there is no comprehension zone (between the it tries to show you that you can change not only the numerals but also the units. in the unit assigned to the result. Machine Translated by Google fifty-eight stations between one hundred and ninety-three meters?] (Write first the divisor 193, secondly draw the galley and finally the stations next to number 58. See Image 31)] Yes. [And these are...? (points to number 193, Image 31)] meters [the first division [And what was this? (points to operation 58/193, See Image 32)] fifty-seven dividend 58, without resolving the operation) 193/58, which would be the same as here how is? (points to division 193/58, Image 32)] one hundred ninety-three between eight meters between one hundred and ninety-three stations [and can they be divided 133 fifty-eight meters [and that gives you three point thirty-two meters]. See Image 29) [These are stations (interviewer writes the word Image 32. Conventional reading of the division Image 31. Difficulty in assigning units to the quotient. Machine Translated by Google result when reversing the data in the division. Even absurd divisions are proposed 134 This reasoning is understood when the logic with which it operates is known. quantities in order to identify the differences in the meanings of the like dividing children between cakes or between bars of chocolate. five 1.5 (also add the remainder 10) [what does this mean?] a bar and 58 seasons] it’s the same [is it the same?] yeah. difficulty of the operating rules of the division algorithm, some conclusion that two out of three [How would you do it?] It would be… (He thinks for a moment and does the galley Andrea: for her it is clear that distances should always be the dividend. Before the [But now if I tell you divide… uh… three bars of chocolate between two children] proof. (points to the first division, 193/58 stations) because the meters go here may be clear to the student she stands her ground until something makes her of the division) (See Image 32) [that is, if I tell you ”divide 58 stations by 193 meters” what The interviewer uses simpler problems, from different fields and with different types divisor) 3/2 [Um… the three bars, can you finish it?] yes, I would give one point you write like this (points to division 193/58] uh-huh [but if I tell you divide 193 meters between (points to the dividend of the last division 193/58, bottom of the image) Differences in results when inverting the data in the algorithm ... the three… the three bars (add the dividend) 3 between the two children (add the Image 33. Awareness of the organization of data in the division. Machine Translated by Google dividend, then the galley and finally the divisor. See Image 32) 10/5 [and what solve the difficulty expressed by Andrea: knowing how to accommodate the data. When typing in [Now if I tell you…divide…five children between ten bars] (Write first the how much would I give you?] I would give two 2 [Two what?] Mmm… two bars. They find themselves in a zone of understanding, where they both share the same goal of the arrangement of the data. In this case, the interviewer asks you to make the division It’s 63 about dividing the children between the bars. The logical and usual thing is what Andrea answered: first the galley, expresses the conflict that must be resolved and shows that he thinks about In this domain, experience dominates completely and does not allow you to realize that the data inverted. media. 135 because that way they will be able to reflect on the result of the next operation with two bars to each child, although the interviewer’s intention was different. First speak ”two out of three”, then think for a moment and draw first the out. galley. This action can be interpreted as both the interviewer and Andrea You are asked to divide children between bars, which should result in children per Image 34. Division of 3 chocolate bars between 2 children. Machine Translated by Google Image 35. Division of 5 children between ten bars. Image 36. Division of 20 marbles among 40 children. similar division, but now with paddles with the dividend less than the divisor. Normally there are twenty marbles among forty children, I would not get one for each one, Since it is unrealistic for children to distribute “half marbles”, a [How do you divide...ten lollipops among twenty children?] Well, the lollipops inside and the they play?] they play…five 5… [Is it possible?] No, but I wouldn’t give it either because that way five [um...um... are you bored already?] No [No?]. they would have to be forty and up. children outside (write down the dividend and then the divisor) 10/20 so it would be a meaning of what divides. Still mastered the logical relationship of the marbles between the In this division we can see that Andrea begins to understand the 136 Twenty marbles in and forty goes out 20/40 (write the number first). number of marbles to be able to distribute them. dividend and then the divisor) twenty marbles divided by forty [How many do you [How do you divide uh...let’s put...twenty marbles among forty children?] children, and not the other way around, but he realizes that there should at least be the same Machine Translated by Google as a dividend the first data stated verbally by the interviewer. Now I know The interviewer focuses Andrea’s attention on the operation of dividing children operation without being prompted) the result is five 5. It does not represent any difficulty for her and until now she has been systematic in writing change the meaning of the relationship. What will be divided are children between meters of ribbon. the theorem-in-act ”the distance in meters corresponds to the divisor” prevails. [Five meters of ribbon between ten children] (Write 5/10 and this time solve the real possibility of dividing meters of ribbon between children. It must be remembered that Andrea meters] (corrects and writes about the previous operation and solves it) 10/2 would be between meters. Andrea orally repeats the proposed division, correctly expresses how he realizes that he operates with another relationship, he distributes the ribbon meters among the children. Now a division is proposed to you with the divisor greater than the dividend and with the [And if you divide ten children between two meters of ribbon?] 2/2 [ten children between two place the data in the division and marks an operation with the same data. But not [Now twenty meters of ribbon between two children] twenty meters of ribbon between two It raises the division correctly, although it does not solve it correctly; besides, Andrea changes the meaning of the relationship: instead of dividing the children among 64 the 137 Consider that the meters go inside the house. five 5 [five what?] m five meters each. [Er... can this division be possible?] Yes [ten children between 2 meters?] Yes (touches his invariance that will become a theorem-in-act: “the first object stated will be the without writing the residue) 10 to ten meters each. that what is first stated is what goes inside the house. on this occasion dividend and the second, the divisor. here it can be seen that it is through repetition that he begins to identify a children 20/2 (write the dividend, then add the divisor and at the end the quotient meters of ribbon distribute the meters of ribbon among the children. Furthermore, it contravenes the idea Machine Translated by Google Given this response, a similar division is proposed, but now with a divisor data order. It is until the next division that questions the possibility of dividing the children and not the slats. Andrea assimilates the relationship and therefore on this occasion theorem of the first stated fact. less than the dividend and then another division with the same data but inverted. Andrea’s answers are based on logical reasoning; she does not attend to Another division is dictated to him to emphasize that he is now being asked to divide well in the logical relationship. his fingers between the sheets that are inside a folder) touch two [and children. children? [See, that’s what I’ve been saying for a while now (laughs)]. It takes the first stated data as criteria to use it as a dividend. It is based more [Ok and a child between two meters of ribbon] (This time he does not write, he introduces [Um... let’s see, how do you divide... five children between...?] How can I divide the ribbon] 10/1 (write the divisor first and then the dividend) touch ten 10 hair) [tell me what are you going to divide?] is divided… uh… the two children (points to the well at half a meter [very good, well the truth is, look, I’m making you 138 [Very good, let’s see if we can do another more difficult one, a child between ten meters high One meter between two children?] (Moves the pen and does not write the operation either) It is a detail that takes time to process, it is a construction of inside (points to the dividend) and the two children outside (points to the divisor and adds Again, the theorem of length in meters prevails as a divisor over the good] (touches her hair and shakes her head). next to the dividend the letter m). divisor) between... (Points to the galley) [Aha] the ten meters of ribbon that would be because ten divided by one equals ten. trick questions to see how you answer, but the truth is that you work very Machine Translated by Google that the divisor represents a length in meters. It is the first time in which that meters… fifty centimeters [uh, how else?] half… half a meter divisions again to confirm understanding. possibility of dividing a child between two slats write the division correctly despite criterion is no longer a priority and also verbally expresses the result in a creative way would you say?] children [how else would you say point five meters?] point five Once both share the idea of being able to divide children between strips, they consider [then we are going to suppose that a child can be divided between two meters of to see if it occurs to you to apply the terminology of other fields different to this one. [and in kilos?] they were kilos... half a kilo, fifty grams [and if they were children?] [If I told you a child between two meters of ribbon] it would be two meters between a child and correct. It does not occur to him to mention half a child. So other 65 questions arise. half a child (laughs) it would be... I just don’t know how to say... well it could be... child who meanings between the interviewer and Andrea in this zone of understanding that little by little half child: 139 ribbon] 1/2 [how much does it give you there?] (Solve the operation) 0.5 would give me about five The following questions explore whether Andrea can express 0.5 of child as Once this route has been completed, the difference is expressed between dividing meters of ribbon problematize the distinction between the order of the data and the result obtained. Andrea expresses that it should be two meters between a child, but in the hypothetical Meters [and if they were kilos? point five, what?] kilos [and... if they were children, how would they Accepts the possibility of dividing the children between the slats and solves it correctly little were coinciding up to this point. This detour was necessary in order to be point five of child. [If they were meters, how would you say it?] If they were meters? [Yes, how would you say them?] V.1.2.3 PARTIAL CLOSURE Machine Translated by Google begins to carry out the operation, writing down the dividend first and then the dividend and then the divisor) 2/4 =0.5 car equals point five car I understand. [Now divide… uh… ten popsicles among five children.] (On a new piece of paper divisor) 10/5 = 2 that’s it [It’s easy, isn’t it?] yes, I already realized that the first [Divide hmm… two cars by four people] (Again add first the we divided two meters of ribbon between a child, did you get this part yet?] Yes, ok, ok above reasoning holds. At the same time, Andrea explains the Andrea expresses that she has noticed that the first word spoken is the [car? Is that what it says?] Yes. of which it knows that the graphical representation will be adequate. Doesn’t mention half a car To consolidate this achievement, new problems are posed in order to observe if the word is inside. It is observed that when writing the dividend, it is focused on controlling this data, from Second hypothesis: The first word is the one that goes inside between children and vice versa. interviewer: the first word acquires the role of dividend. Andrea was able to 140 generalizations you made during the interview. divisor, which is correct in the divisions stated orally by the as the interviewer would have expected. and you say that it touches two meters, but no, because what is being divided is the child dividend greater than the divisor. with previous relations, changing the scopes and Andrea solves them correctly. and we divided that between the two meters of ribbon, it is very different than if [Notice that a while ago I asked you ”how much was a child between two meters of ribbon” It begins with a simple or intuitive division: distribute popsicles among children, and also with the recognize this invariant and also make it explicit. More divisions are proposed Machine Translated by Google Robert and Balslev (in press) mention regarding the meaning that is discussed and correctly the result but it is the interviewer who considers that it is incorrect. then it would touch a quarter of a pie 0.25, point twenty-five [let’s see, in an inverted way; does not carry out the operation but by mental calculation obtains 0.5 and four divided by two] (write the dividend and then the divisor) 4/2 [is that easy? Because there are four children between a cake, or else it would be the other way around (write the aptly as a quarter. hand the division 4/2= 0.5 children, to solve the operation again)] four sheet) 4/1 66 aahhh… 4 to four [four?] four children (write next to the quotient) It is notable how Andrea inverts the direction of the division and in case of dividing a 25) [are you going to divide four children between a cake?] yes, the four children are divided giving the same result: because… the children are the ones that are divided by four [mmm… no] yes [no] built by the different participants: Andrea does not accept that she is wrong and defends her position. It shows what Saada explain it to me again, it’s very interesting] (silence) [to see four children between one mentions that 2 children between 4 cakes would be 0.5 children, which is correct even though the 141 divisor, then the galley and at the end the dividend) 1/4 [I don’t know, let’s see] yes and In the next division it is the interviewer who makes a mistake. andrea express In the following fragment it is observed that a simple division of 4/2 is interpreted by pies between two kids oh no I mean four kids between two pies [divide there kids [let’s see, there’s a mistake there] no, it’s okay because it’s one times four, four. pie between four children anticipates very well that the result would be 0.25, which he interprets [Let’s see, and four children between two cakes?] 4/2= 0.5 children [why does this give you?] No? [let’s see, there (takes the pen and gives it to the interviewee, then covers it with the [Now four children between a cake] (Write the operation again on the pie] would be to point twenty-five (point to the operation you just wrote 1/4= . between one [and four children between one gives us four] yes. Request was to split 4 children between two cakes. You are prompted to repeat the operation and continue Machine Translated by Google write down the remainder 0) [so you said they were boys] oh, yes, two boys, that’s quickly) 2/4= 2 children [but finish it all, how do you divide?] two after the divider) 40/80 [doesn’t they become difficult for you anymore?] (He makes a movement with Once you have managed to build this action rule, you are presented with a problem 142 [Um... let’s see... how do you divide twenty by fifty?] Twenty by fifty (points to the 20/40 split)] yes, but this is very different because…uh…it [thirty minutes?] (Nods) no, maybe and I’m wrong because Andrea can now graphically represent the division that is expressed to her in a (Write in the following order: the dividend, the galley, and the divisor) 20/40 [ago [Er... five pesos between twenty meters] (First write the dividend and the final This... How do we do to... know if... a person in an hour manages to do how long does it take to make a drawing?] Hmm… How many drawings? [Twenty] that I got balls here (points to the previous division 4/2= 0.5) [okay, are we going by two, four and zero left over (this time he does the complete procedure and the head of denial). where the first stated data does not have the dividend function for the purpose of 20/50 [you won’t do it and… forty between eighty] (add the dividend and division?] yes [do it] (gets 5 again) [let’s see, again] there is…is it… two (writes The first thing you tell me is what goes inside [aha]. would be…sixty-twenty in (write in another order, the divisor in the first orally, as shown below: for a while you told me that the meters go inside, that the distances go inside twenty drawings?] But... like... in an hour you have sixty minutes... [How much (Write the dividend and then the divisor. See Image 34) 60/20= 30 min understanding?] yes. The following intervention tries to compare the first theorem-in-act with the second the divisor) 5/20 [wow] 67 (laughs) [Ehh… twenty kilos between forty people] challenge your hypothesis. Machine Translated by Google were thirty minutes, it couldn’t be because... if not, it would only be minutes [the what?] hour (he thinks and writes next to the quotient) = 3 min minutes, it can’t be, and this one? (points to 0.3 hour)] well, it’s period (to the quotient 60/20= 30 min)] would be twenty minutes between… (He thinks for a moment and stays [Because? Let’s see, what are you going to divide? (hand covers anterior division quiet) would be… [Let’s see] (Silence, write 20/60) [Yes, you can do these add a zero before the three) 0.03 which means 0.3 hours (one tenth is equal to 6 Are you doubting? It’s okay because it’s not a common question] but yes minutes, 0.3 tenths is equal to 18 minutes). divisions?] Yes 0.3 is to point three, (drops pen on desk) [point three 143 place 60 and after the dividend 20, See Image 37) 20/60 Image 37. The first item of information stated is not always the dividend. Image 38. 20 minutes between 60 seconds is equal to 0.3 hour and this is equal to 3 min. Image 39. Adjust the ratio as required. Machine Translated by Google 144 conversion and applies his rule: the first item of data is the dividend and he obtains as data of the hour that appears first is not the dividend; on the other hand you have to minute because what he divided were minutes and not hours. The interesting thing is that at The foregoing shows that, in solving a problem, not only results in a [what does point three mean? (take the pen and write .3 hr = 3 min, See properly, the operation and also returns a correct numerical result, but the Determine how many minutes “0.3 hour” equals. The interview then takes another basic and whose difficulty is widely reported (Charles, 2011). cover the division so that she orally expresses what she will divide and then the rule procedure is only applicable to a decimal system and the hours and minutes are based on it’s 3 minutes. Andrea generalizes the procedure to convert the units of quantities and their relationships. very unlikely to be used in school or everyday life, but involves the result 30 minutes. When the interviewer repeats the result back to her, she considers that convert to minutes and the quotient is a decimal less than one. she does the ask him what that result means, he says ”point three... hour” and makes the equivalence to obstacle the mechanics of the algorithm, but also the interpretation of the units of the Image 37)] this point three... then... point three would be from before... it would be... interpretation of the unit is not because instead of 0.3 of an hour it would have to be 0.3 of The impromptu problem causes Andrea many difficulties. On one hand, the direction: clarify how much 0.3 hours is equivalent to in minutes. [Well, this brings us to trying to understand what point three o’clock means] yes above can be effectively applied in this case. She represents in writing, a sexagesimal system. Realizes something isn’t right, but it’s complicated She tries to convert what she considers to be 0.3 hours to minutes. It is a content with use of rational numbers that must be understood by education students there may be an error and then it hesitates, inverts the data in the division. The interviewer minutes as if it were a conversion from the metric system and expresses that length from meters to centimeters to hours and minutes. However, that quotient and also plays an important role the scope of the problem, the magnitudes, Machine Translated by Google 68 Image 40. Graphic representation of three tenths of an hour. and that the set of ten tenths form the unit. the bar that divided. See Image 40) [why do you divide it by three?] Because it is rational numbers, knows that 0.3 is equal to 3 tenths and that each tenth is less than one It coordinates very well the different forms of representation of the decimal fraction: 145 in three the bar drawn on the sheet) would be here (write .3 in one of the sections of because then we mark point four 0.4 after 0.3). the 0.3; on the other, it establishes the equality in writing between the decimal number and in the form of equal to a third of an hour 0.33 =ÿ [ah, what if it were point four?] it would be around here On the one hand, in the bar that represents the integer, it marks the approximate point where it would be. Andrea, despite having spent almost an hour in the interview, is very interested There are ten tenths and of those ten tenths it will not reach one... the tenths third of an hour. This is an example where the different forms of representation, fraction 0.33= 1/3; In addition, he verbally expresses 0.33 correctly: ”is equal to a tenths [if we wanted to convert it? imagine this is an integer (draw a notes that he has a good command of the subject of decimal numbers and some aspects of conceptualization of the mobilized mathematical content, in this case the use of numbers horizontal bar)] yes [where would three tenths be?] (Takes pen) divide are equal to one, then (points to the 0.3) [so what is the point three?] three in understanding and learning, she is still very active and committed to the task. HE Oral language, writing and the iconic representation of the bar coincide with the Machine Translated by Google Image 41. If a tenth of an hour is 6 minutes then 3 tenths are 18. six because there are six in every tenth of an hour [mmm… that is a bit difficult and time operates on that result to convert the decimal fraction to minutes, you get 18 and [Well, just so that we can move forward and clarify things, if this is your because it is divided... no, it is by six! Or point six? [Point six or six?] No, it’s five point of an hour?] would be… mmm thirty 30 [What’s that called?] thirty divide it by 10; first it approximates saying that it is seven, then it corrects and at the same hours is equivalent to multiplying 6 minutes by 3: divide by ten [by ten, well, they are already divided, so we count three] you understood him, right?] yes [they are things...] I understood him better [have we gotten tired yet?] 146 whole and you have tenths, it means that you make ten little pieces] then you can minutes (add the word) minutes point five equals half an hour [already pen and think for a moment) [How much would be an integer? How much would it be?] rational. one, two, three [okay, so what would three tenths of an hour be?] (Take the hmm… not yet. necessary to give an explanation about the meaning of tenths. From there Andrea three (write in the following order) 0.6x3=18 min [why for point six?] is integer is divided by 10 and the integer is an hour, you need to convert it to minutes and then very quickly deduces that a tenth of an hour is equal to 6 minutes and therefore 0.3 In order to continue with the theme of the dividend and the divisor, it is done One hour [and point three?] seven [eh…] No!... then it would be point six times Andrea does mental calculations with some precision. For example, deduce that if the Machine Translated by Google 147 who has understood the relationship between the decimal fraction 69 of an hour and its conversion to He mentions that it is six because there are six in every tenth of an hour. Andrea is asked if hour and she answers that 20 drawings out of sixty. If you correctly solve this drawings?] twenty, so to verify multiply twenty by eighteen x 20 how many drawings does a gentleman make?… he makes twenty drawings in an hour, how much is going to divide by what to determine the order they will have in the division. When commenting on this gives eighteen (indicates the corresponding operation 6 x 3 =18 min, See Image in a problem the data and you have to accommodate them; so how do you now she is able to spell it correctly; However, when faced with a [Well, just to confirm, I had told you that... do you remember the see another very interesting theorem-in-act: consider that if the values are changed correct?] I could get something less than twenty... (Silence again) [Let’s see... different from solving a problem, we were already making divisions where we already minutes, at least at the level of tenths. knows how much 0.5 of an hour is and she answers correctly. It is a way to check division, what you would get would be the drawings you make per minute. To suggest that you [How many do you think? More or less?] Eh… (He thinks about the answer for a few minutes) How long does it take you to draw a picture?] Well… [What do you have to divide by what?] He is asked what he would have to divide to find out how many drawings the man makes in one Write the unit in an abbreviated way: 18 min. Lets see the calculation made when 38) [and if it takes eighteen minutes for each drawing, then how many do you know? What are you going to divide and between what?] Mmm… uh… [Look carefully, word problem and she has to decide how to arrange the data, she must think about what questions?] What was it… was it point three? Then multiply by six and twenty minutes between an hour, why did I ask you this question? because it is very do you know how to write the data if I dictate it to you...] yes [but it is very different if you see In the following fragment, Andrea is explained that if a division is dictated to her, correct is reverse division you are asked what would happen if the data is changed. she leaves numerical in the division the units of each one remain fixed: uh... I don’t know [How much do you expect it to come out?, How much would you add to it to come out Machine Translated by Google draw a boy next to the number 10) yes, here are the ten boys (ten years ago (write the dividend and then the divisor) 60/20 would be… [And if you change it?] [how do you divide?] there are twenty pesos between ten children (points to the divisor and dashes to symbolize children) and here are the twenty pesos (draw 148 you say I’m interested] (laughs) they are… if I put the sixty inside and the twenty outside previously) 20/60. each dash that equals children. See Image 39) then it would be two So it goes twenty between sixty (points to the operation that he had already written twenty dashes and begins to group two lines that represent the pesos per [Um... let’s try what you say... if you have twenty pesos between ten children, Twenty out of sixty [twenty drawings out of sixty minutes? And would it matter The interviewer explores this idea and tries to prevent Andrea from staying with it, through the following questions: [to two…]. sixty drawings between twenty minutes [ah… but then the reverse changes] yes division (covers the quotient with his finger, See Image 39)] (keeps silent) (Write the dividend 70 and then the divisor. (See Image 42) 5 children [you change [let’s see, let’s see that is very cool, what you are saying to me, everything that if you divide sixty minutes by twenty drawings?] No, because then it would be how much does it give?] twenty pesos 10/20= 5 gives five [five?, why?, let’s see, do well [Let’s see, what would happen if we divided ten children among twenty pesos?] 10/20 Image 42. Iconic representation of 20 pesos among 10 children. Machine Translated by Google complete are two pesos] yes. they went inside and the rest outside?]. Yes, later I said that the first thing you said was what went inside and the rest went Does it touch point five?] Yes, for each peso it touches point five children [and for the child It allowed him to express and modify his hypotheses about the division. Recognizes that 149 To summarize, Andrea manages to reconstruct, together with the interviewer, the process that outside (points to the operation in Fig. 11) there it is fine [yes, it is fine there]. divisor, but he also recognizes that the idea that changing the data in you said that dividing twenty pesos between ten children gives you two pesos] yes [but if you some of them were correct, such as: the first thing that is stated is the ten pesos between twenty children (he affirms) [so, you can change… divide twenty [Well then let’s take a tour, first did you think that the meters pesos divided by ten children or ten children divided by twenty pesos, is it possible?] yes [then change means that here I am dividing ten pesos between twenty children] the division units remain fixed: Image 43. Division carried out under the theorem-in-act, the meters are located in the dividend. Machine Translated by Google Image 44. Division carried out under the theorem-in-act: the first item of information is located in the dividend. V.2 CONCLUSIONS OF THE ANALYSIS . reformulation. meters and depending on how you want to divide it is how you are going to accommodate it. his theorems-in-act, put them to the test and, as far as possible, promote their Well, what are you going to divide by what... you can divide meters by steps, steps by this… we took a long time but it was worth it] yes [thank you]. Note: The interview Andrea, we can now infer new explanations for why students choose to Are you going to forget?] no [well...] now for the other one [you worked very well, thank you very much, Based on the microgenetic analysis carried out in the resolution process that makes From this tour, it is possible to notice the advances in terms of difficult to assign units of measurement to the numerical results obtained. lasted 59 minutes. the 70/35 split instead of 35/70 (not just because it’s easier) and why you find it but what’s wrong is that I said that if things change it’s still what a personalized approach to Andrea’s resolution processes to identify same, but no, things change [everything changes, so you should always think changes in the meanings of both the interviewer and the student. It required 150 Machine Translated by Google 151 mathematics, leading them to relate biunivocally each element of the expression consolidated, students use theorems-in-act from other areas that already Thought, in Vergnaud’s (2004) terms, consists of operations both requires then a long-term didactic work that allows students to It is important to highlight that it was through the scaffolding provided by the interviewer, identification of invariants, construction of action rules and their subsequent The difficulties that Andrea experiences are due to the 71 flimsy construction of a part of all the relationships and meanings that must be contemplated in the resolution graphically the inverted relationship. give meaning to what he does when, on his own or through the intervention of the teacher or in that have links between them and with the meaning, then Andrea shows us how confrontations to different situations in which they have to use various systems The use of the calculator could only be a support as a complement to these verbal with a graphic signifier in a linear manner and from left to right, which dominate, such as those of the alphabetic writing system to write the notation conceptual as pre-conceptual about the meanings and at the same time about operations realize the limitations of their conceptions and, therefore, delve into the through specific questions regarding the difficulties observed or errors committed generalization, and if necessary, its reformulation. If we consider that the Faced with situations that involve concepts, notions and procedures not yet the concepts involved during the resolution and not to ”their ability to reason”. of a math problem. It is important to highlight Andrea’s intense surgical activity through the In this case, the interviewer realizes an error. symbols to find the regularities and at the same time identify their differences. reflections and on par with the domain of algorithms. However, it only refers to causes that before a correct verbal expression of a division is represented symbolic on the signifiers, which form several different symbolic systems, employs the different symbolic systems of representation, operates with them and tries to detail of the mathematical contents and written algorithms, through Machine Translated by Google a very difficult task due to the working conditions in which he works: the number of concepts and theorems-in-act that lead to the understanding of the problem, as well as the the student to confront their ideas and manage to overcome them. This would mean for the teacher students per group, the large amount of content to be addressed in reduced times, because the interviewer has a referent of how relationships evolve between different level of complexity (Flores 2005). labor. However, you can find some strategies such as working in pairs, influence of the conceptual aspects that give rise to the problems having a extra-class activities and, finally, what Elsie Rockwell calls the double day as observed with Andrea, show cognitive activity to make sense of the by Andrea, that her theoremsand concepts-in-act are made explicit and put to the test 152 The errors that students make when facing a mathematical problem, group reviews, etc. having generated rules of action that were not very productive in resolving situations underlying reasoning and from that they would propose new situations to help belonging to the same conceptual field. This scaffolding process is possible thanks to for her. Otherwise, they could have remained for a long time and, therefore, faced situation. It would be very important for teachers to reveal the Machine Translated by Google understanding the relationships between mathematical conceptualization and systems of as well as in Andrea’s microgenetic analysis (See Table 11). The results gave us an overview of the responses of the 329 students and the representation, which in the experimental phase remained at the level of inferences, we chose experimentally, we build some observables to explore in the analysis of the 30 The clinical interviews 72 are part of the second phase of the field work and are This time allowed us to do statistical analyzes to find similarities and differences of Based on Andrea’s microgenetic analysis and with the results of the phase clinical interviews. The data was classified into 12 themes grouped into 4 aspects of conceived as a methodological resource that would allow us to delve into the according to the variables that we included in the methodological design. To delve into 153 the resolution of the problem that was highlighted as important in the experimental phase interpretations that we made from the results of the first phase, whose Problem Relationship between the symbolic-concrete planes Algorithm reading with alphabetic directionality Units Mathematical writing with alphabetic directionality Algorithm mechanics Empirical feasibility Calculator, orality/writing Result Problem figure Autonomous drive allocation Thematic dividend greater than divisor Autonomous check division algorithm Correct and autonomous resolution of the problem Carrying the decimal fraction to unity clinical interviews CHAPTER VI. Results of the analysis of Table 11. Classification of data from clinical interviews Machine Translated by Google Table 4. Distribution of clinically interviewed students experimental there was a process of preliminary analysis of the results to prepare the They are in the biggest or the smallest, so he says that it is best to start with (the group application and the interview) was varied, because after the phase mention that they are the simplest facts. But he wonders if the simplest facts explored. In the case of high school it was a period of one month and in the case of primary schools, In this way, in the categories that were elaborated in the experimental phase, one to two weeks apart. clinical interviews, choosing the students who would be interviewed and the topics to be the regular cases. In total, 30 students were interviewed as shown in Table 4. In that It is necessary to remember that the students interviewed had already faced this 30 students whose answers were located in the categories defined in the analysis We review the cases and choose those prototypes of their category. 154 For the selection of the students, we follow the recommendations made by Poincaré (1963) for the selection of the facts to be investigated. He suggests selecting the previous chapter, so it is also accounted for in subsequent analyses. asking them if they remembered their result. The time elapsed between the two moments the most interesting facts and they are the ones that can be used several times. Besides statistical. Andrea is also included in the total, although a description of her case has been made in same problem in group app. Interviews are usually initiated Primary Level 8 17 Total 8 Total 17 13 9 13 30 Men women secondary 5 Machine Translated by Google Problem Correct and autonomous resolution of the problem 15 50.0 Thematic 6 20.0 Frequency Percentage problem figure 24 autonomous check 80.0 VI.1.1.1 FIGURE OF THE PROBLEM: PROPORTIONAL RELATIONSHIP VI.1 RESULTS ACCORDING TO THE ISSUES IDENTIFIED VI.1.1 PROBLEMATIC Table 12. Issues related to the Problem category student to deal with the problem. It is taken up from Pierre Gréco (Gilis, in press), who quantities, which we infer from the resource of division, however it is interpreted. The Figure of the problem is considered to be the first resolution scheme executed by the developed a figure of the problem in 73 terms of proportional relationships between both relations. This item groups the data related to the topics on the interpretation approach generates a provisional mental model of it that activates one or more In his model of the cognitive functioning of the subject, he proposes this term to express will pose; it is considered that they were 24 of the 30, 80%. The rest established another type of 155 the subject’s first approach to the situation; according to him, from said related to the resolution process and the autonomy to explore a Starts making adjustments based on new data initial problem (which we will call problem figure), also the data schemes that correspond to that first model of the situation. In this way the subject The table above shows the frequency with which students who verification of the obtained result. incorporated as the activity progresses. Machine Translated by Google Can you solve it again and tell me how you did it? Pray?] Héctor walks... In from right to left) Twenty in... (1F). subcategory Split 20/40, although at the time of writing it represented [... this problem, right now I’ll show you how you solved it. Do you remember?] Yes [Do you that its result will be point five. Therefore your answer was classified in the first [Umjú] No, just... divide forty [Uh-huh] Well, divide twenty by problem, the interviewer asks you what you understood about the problem and then how you would go about one minute Hector walks twenty meters and takes forty steps, the size (1F) the steps he took and it’s going to be point five (2P) [Umjú. How do you remember? 156 In the initial part of the interview, after the student has read the To make a better description of this initial ”configuration” of the problem, it is whether verbal or written, was the one considered to integrate these 8 types. 40/20, first the dividend 40, then the galley and at the end the divisor 20, that is resolve it, or immediately start your resolution process. The first expression, Let’s see, how did you do it? Do that division, you divided what by what?] (Write solve the problem (See Box 12). then it does: He mentions that to solve the problem he will divide 20 between the steps and anticipates sub-divided into 8 types based on the first scheme activated by the students to For example, Gustavo remembers how he solved the problem, explains his process, and 5 c. 35/70 20/40 split without filtering time d. Rule of three e. Deduction to. Division 35/70 20/40 1 1 3.3 problem figure Frequency Percentage 29.9 F. multiplication g. another interpretation b. Split 70/35 40/20 1 40 3.3 12 1 3.3 3.3 9 16.6 Table 13. Subclasses of Figure of the problem Machine Translated by Google What he did to solve the problem was divide 20 by 40: resolution route verbally. This does not mean that this is actually the case. during the resolution process when new relationships are identified, new Example: Irene, a high school student from an urban area, mentions that she Hector walks twenty meters and takes forty steps, on average what It means that you have reconfigured a representation of the problem and posed a specific schemes to deal with it. This first approach often changes to. Division 35/70 20/40 (12 students) well, but I would like to know how you did it] I don’t remember [Umju, let’s see, well represented in writing and solved the algorithm. From verbal approach to resolution as illustrated by Andrea’s microanalysis. data or when difficulties are encountered along the way. size are its steps [Umhoo, that’s the problem you solved and you solved it In the 74 end, there are several possible paths to follow, depending on the difficulties encountered, first approach to the problem, they expressed that to solve it they would divide 35 by 70 or 40/20. This variation could be caused by other aspects that will be analyzed further. twenty out of forty 157 The results of the clinical interviews show that 40% of the students, in a try to figure it out] (thinks for a moment) I can’t [You can’t] I think I divided b. 70/35 40/20 split (9 students) In this way, by figure of the problem we understand the first configuration of the Students proposed from the beginning the appropriate procedure to solve it. reflect on him and mentions that he can’t. Finally he says that he divided 20 by 40. problem in which some operative invariants are identified that allow to activate forward. 20 out of 40, as appropriate to the version of the problem. which means that 12 Irene says she doesn’t remember how she solved the problem. try to go back to Machine Translated by Google Antonio, a telesecundaria student, says that he divided 40 by 20 and got They initially proposed dividing 70 by 35 or 40 by 20. There are 8 students who he... this... walked and took forty steps [Umjú] It’s the same thing I did [He’s verbally that he divided 40 by 20 and when he writes it he does it in a conventional way possibility of a dividend less than the divisor as in the case of Luis Antonio. (2P) half a meter [Umjú] That was what I did and then to verify what it was, to understand…]. raising this division. It means that they possibly identified among the data of the and he takes forty steps [Umjú] On average, he says, what size are his steps? I happened?] Five times two... ten (1P) forty, twenty, (1P) point five... [Umjú] did] I divided forty by twenty (points to 40 and 20 as he could be oriented by the theorem-in-act ”the dividend is the largest number in a step that is correct (half a meter) and the result through the written algorithm. as 0.5, which he interprets as half a meter: established this relationship and represent a quarter of the total. Example: Louis very easy, right?] Let’s see, do it (Perform the 40/20 division. Start from right to There is no variation between both representation systems. The problem that 158 I multiplied those points five by forty [Umjú] (1P) which were twenty meters that In this subcategory were classified the data that expresses that the students As can be seen, Luis Antonio, unlike Gustavo, expresses problem a proportional relationship but when proposing a division they do not consider the Um... I divided forty by twenty and it gave me uh... zero point five, right? That (Pause) [Okay, what’s the problem? Don’t worry huh, we’re trying division”. For this reason there was no correspondence between his deduction of the size of a The results show that 8 students started solving the problem [How did you go about solving it? Try to remember] Héctor walks twenty meters left by the dividend, then the galley and finally the divider) [Let’s see, how mentions) [Umjú] He is forty out of twenty [Umjú] (Pause for a moment) [What you are facing is that you are not getting the result you expected. Your initial resolution scheme Machine Translated by Google again the 70 that appears in the problem), uh... what came out, what d. Rule of three (one student) by 60, which correspond to the sixty seconds that make up the minute mentioned in the trein... No, the 35 (point to the 35 that appears in the problem) among the 70 (point to I multiplied by 60. problem without this data. that he divided 70 75 by 35, although he corrects it immediately, and that the result was multiplied by [I would like to see how you solved it] How did I…? [Uh-huh] It’s your initial resolution process. In the experimental phase of this study, it was shown that María de los Ángeles was the only one (of the students interviewed) who raised analyzing the situation through an iconic representation of the problem, putting problem text: Ruth was the only student of all those interviewed who considered the time in initially a proportional relationship through the rule of three. Starts saying? Seem to you? Or do you want to see what you wrote and explain to me what you wrote, c. Split 35/70 20/40 unfiltered time (one student) problem with distractor and those who solved the version without distractor. the time data, 159 I don’t remember... [You don’t remember, and if you solve it again and you give it to me? There were significant differences between the results of those who solved the version of the in correspondence the distance in meters with the number of steps. Then try to do resolution taking into account the ”distracting” data of time. the meters [Aha] and I divided the 70 (point to the 70 that appears in the problem) by fewer students solved it correctly, compared to those who faced the This is Ruth, a high school student from the urban town. she mentions This subcategory is similar to the first; However, the student began the process of yes?] Yes [Let’s see, what did you do? Let’s see] It’s that, well, I made an approximation of that should be discarded because it does not enter into the pertinent relationships, was the reason that Machine Translated by Google 1 under the seventy, it is a rule of three, then write the division 35/70, put multiplication 60x35) More or less like that (laughs), because I don’t remember [Aha, [Well yes, if you want, how many are there? In centimeters] Ah, well... (Write 70, 35 and a zero in the dividend and a point in the quotient, write seven next to it.) Seven (Draw a line and a doll, write 70 steps and 35 meters, then write the the numbers, so I always put little drawings [Ah] And that’s how it’s represented write the answer “0.5 meters”). So? [Umhoo] And now [Yes] Wow. ok, what did you do here? First... talk to me] It’s that good, I... I get bored with times seven... no, seven times three, seven times four (write 5 in the quotient, to the side distance of thirty-five meters [Yes] And this is his race tape [Ah... good. a conversion from meters to centimeters to consider in which units the Until the approach of the rule of three, there are three aspects in the resolution process of María de los Ángeles that are worth highlighting. The first is the change in planes of easier [Umjú] That’s why I put Héctor who takes seventy steps [Umjú] And this is a Although we could consider the figure of the problem from the drawing made correct result: 100x35) [What?] Isn’t it? A... because they are, do they have to be removed in centimeters? 160 result. Finally, correctly state a rule of three, do the division and arrive at the And then, here you did....] Well, you have to take it out... Oh no (write the multiplication representation; goes from an iconic representation of the problem to an approach Image 45. From iconic representation to the rule of three. Machine Translated by Google some written operation. 161 algorithm correctly and makes an appropriate interpretation of the result. that he found among the quantities and concludes that he takes two steps per meter without making It’s supposed to be thirty-five meters. In 76 about thirty-five meters walk same relations defined in the rule of three. The third refers to the fact that it resolves the pass the data from the rule of three to the division algorithm correctly. They are thirty-five, so he takes two steps for every meter. [Very good] (Laughs) [It’s In the corresponding section, an analysis of its procedure will be carried out to seventy steps. The seventy steps uh... which is supposed to be half of... of seventy They analyzed the problem and were able to estimate the size of the step, practically by correct and conventional rule of three, one of the most sophisticated tools that [Umhoo, or what you said, so I don’t forget. Ah, yes, yes] (Writes) [Then and. Deduction (6 students) easy, right?] Aha [Now, could you answer it?] I’ll just post the answer or... correctly the proportional relations and in the same way, the written algorithm Example: Yéssica, from the telesecundaria school, verbally expresses the relationship half of 70 is 35 and takes 2 steps for every meter of the division with the data placed appropriately, that is, maintaining the used by students in this study. The second aspect is that it represents Mental calculation, establishing the relationships between the corresponding quantities. for you it was very easy] Hmm, not that much, but yes. Image 46. Yéssica’s response obtained from a process of deduction and mental calculation. Machine Translated by Google manages to give a correct answer without having to resort to other planes of representation in correctly, but when they pass to the level of written representation they fail to maintain urban town. walk twenty meters and give forty, it would go too far [If it were one meter, it would go too far] 162 half a meter. Well, that was exactly how... how you wrote it, right? before you thought the students did not. Even so, they made a first interpretation of the in the following way: if you advance 35 meters and take 70 steps, it means that if you took steps forty steps, I put that his... that his... that his steps are... must be of Don’t worry, that’s why we also wanted to work with you, so this... nothing quickly, very well, that is the correct answer, really very few succeeded These 5 sub-categories group the responses of the students who achieved the initial phase of the interview. homomorphism between the planes and face several difficulties. In this case, Jessica [... Do you remember the problem?] Umhoo [Yes, sure?] Yes, yes [Let’s see, could you Umjú [Then how did you know they could be fifty] Because... half... As in the case of Carlos, a primary school student at one of the schools in the We have noticed that some students manage to do this mental calculation that one meter and you crossed it out, why? Do you remember?] Yes, because if he says yes problem that allowed them to explore some paths in resolution. of one meter would advance 70 meters, as it traveled half, then the size of the step is fifty centimeters each [Aha, come on] (Write “50 centimeters”) [Very solve like you did and you didn’t need a calculator?] I turned it off. establish a proportional relationship between the quantities of the problem. In the other three, There are students who solve the problem by deduction, they frequently operate solve it again?] (Takes up the pen and reads silently) [You solved it very well, but I want to see how you did it] It is that here it says, if you walk twenty meters and give because half, if you take forty steps, it will take you twenty [Umjú] Well, you did it very Machine Translated by Google Image 47. Representation 77 of the relationships of the problem through a number line. From 1 to 5). Hector walks thirty-four meters and takes seventy steps, on average what write “35” at the bottom, divide the line into five segments, number them [Can you read out loud, please...?] Name... [No, here, here...] In a minute No... [Let’s see, you can read it again] In a minute Héctor walks thirty steps would be five meters [Mmm... let’s see, write it down, your answer] (Write how big are your steps? [Yes, right] Umju [And do you remember how you solved it?] I think I did it like this [Umho, how?] because seven times five thirty-five, their [Could you solve it again? (hands him a pen)] You solved the other one well, F. Multiplication (a student) 163 and five meters and takes seventy steps on average, how big are his steps? “R=5m.”). technique. She writes the data and then draws a number line that represents the 35 matter, you can do it again] (Write 1=35m=70, draw a line, to the center and meters and initially divides it into 5 segments: In this subcategory, the interpretation made by Irasema, from the secondary school, was integrated. that’s why we want to see how you did it, maybe you already forgot, but no Machine Translated by Google Image 48. Successive multiplications to find the quotient. urban locality, performs the same strategy, but unlike Irasema she operates with As it finally ended up operating with 7 steps and 35 meters, it was considered reverse of division. In the experimental phase, Frida, a primary school student from the actual amounts and through written calculations. This example also shows the interprets them as 5 meters. problem. However, the strategy is adequate. puts two in correspondence memory. a new type of answer for this data, because it includes a different quantity than the one in the utility of the graphical representation, helps to maintain control of the activity and the we can infer that he is doing a division mentally and therefore loses the From his description, it can be inferred that the relational calculation he made could be the 164 quantities and look for a number that multiplied by one of them gives the other quantity, 70 to reduce the difficulty of the calculation, but then forgot that it had only been a form problem should have found a number that multiplied by 70 would give 35, which is the operation to abbreviate, which were not seven but 70. That is why he concludes that the numerical result is 5 and following: he looked for a number that multiplied by 7 would give 35. He decided to use 7 instead of control of its activity by using other values. If you have operated with the amounts of the Machine Translated by Google Image 49. What is meant by a step. that the size of a step is from the toe of one foot to the heel of the other, instead of asks to solve the problem and only answers that the steps are ”medium”. The interviewer asks him that if the question of the problem had not been about what is. However, most of the students thought of it as a no-brainer. Gabriel believes assumes that the displacement of a reference point such as the person’s head I would divide 35 by 70. consider it from heel to heel or from toe to toe. This is adequate reasoning if one size are the steps but how long each step is, what would be your answer. Say what travel is reduced by half compared to other reference points, for g. Another interpretation (a student) (it would correspond to Case 1 of the step definition, page 63) but as the distance 165 First, he wonders what a step is. As we have already seen in 78 the section on the so defined. After it is explained to you what counts as a step, you will be analysis of the problem, of a very pertinent clarification and although it seems trivial, it is not Gabriel, from an urban elementary school, makes a very peculiar interpretation of the problem. In example the heels or the tips of the feet, it would not be possible to advance 35 meters with 70 steps Machine Translated by Google to determine that the steps are medium. But if precision of the measurement of intensive quantification of step sizes in which, somehow, it must have arithmetic. It seemed strange to us that in a school context, with a mathematical problem they probably did understand it and that they were also able to make an interpretation classified in subcategory 2. However, once you perform the necessary calculations, of the present work we have detected this type of responses, which at first we had type of response and represent 22% of those who considered that they did not A similar case is that of Laura, a telesecundaria student. she input explorations of the answers of the students, both in the investigation “Los lectores amounts. Once the question is specified (as in the case of Gabriel), the relationship between the Otherwise the question would have been the size of the steps, it is likely that they would have mathematical tools to do it, but they did not consider it necessary, as each step, then it proposes the appropriate division for it. consider the data of the problem, establish some kind of relationship between the quantities This type of response was given in students in the sixth grade of primary school and third grade of secondary school. different from the text of the problem, considering that the size of the steps can 166 considered as an ”intensive quantification” in which calculation was avoided Therefore, the first interpretation, his figure of the problem, orients him to a they understood the problem. However, we can now understand that very proposes to divide 70/35, so his first interpretation of the problem is and their contexts” (Vaca et al., 2010), in the pilot study, as well as in the experimental phase The results of the experimental phase show that 18 students gave this required to make a more precise calculation. It is not then that they lacked It happened with Gabriel. This data is very important for this research, because in the different Now we know that it may be due to the interpretation that is made of the problem because, a quantities and arithmetic calculation is used proposing the appropriate division of the express themselves with language terms such as ”small”, ”medium” or ”big”. yes for him Machine Translated by Google thirty-five meters (1P) five, are seventy [Umjú] Which is equivalent to seventy therefore they do not represent the entire sample. Your selection was with the criteria above I don’t remember, I think I divided seventy by two and then... here number and that already gives me (1F), so he walks thirty-five meters that... Steps. Eh... and your steps are (1P) on average, that’s why I put that already, Remember that these 30 students were not randomly selected and you did to solve it, it’s not that it’s right or wrong and so] I don’t know [Umju] It’s just that who walks thirty-five meters, then he takes seventy steps, then... I don’t know, meters each step. mentioned and the intention was to delve into the different moments of the process of asked how big his steps were] Umju, so well... I mean, he says I put it medium because... more or less there it gives you that they were about two 79 167 go...compare with what you did...as you can think of] (Starts to concludes that the steps are 2 meters and adds that on average they are For Laura, in the text of the problem there are two questions: on the one hand, the average and that I divided it and... [Don’t you remember? Why don’t you try to figure it out? and then [...yeah, I don’t think you remember how you did it to solve it, uh... put your that... that is, I put about two meters each, because... it gives me a 2 meters, adds that they are medium. name, please] (Write your name) [Our idea is this... to know how medium: solve it in silence, he writes 3, but crosses it out) His steps were... this... of I mean on the other, the size of the steps. That’s why once you get to the extent of the step of Image 50. The word average refers to measurement and size to an intensive quantity. Machine Translated by Google most frequently related to the domain of the algorithm and its representation conditions of the situation are different. In the group phase, students could concepts-in-act related to situations of proportionality that allows them to But the difficulties that prevent them from having a correct resolution are graph. When this is mastered, the problem is adequately solved. experimental, in which only 34% succeeded (113 of 329). It must be considered that the students, in what Vergnaud considers the epistemic part, there are theorems- and to face it. In this category are grouped the cases in which the students give an answer commit or not to its resolution more freely. Instead, in the interview observed and evaluated, in addition to the fact that the resolution processes and the interactions with the interviewer were videotaped. This and other elements such as non-random selection identify the problem in this way and choose some of the available tools clinic, due to their individual character, could feel more committed to feeling of the problem that have been made, that is why it is important the initial configuration that is resolution that stood out in the results of the analysis of the experimental phase of 50 cm or ½ meter) and that also specify the unit of measure. solve the problem There are a wide variety of ways to represent it to yourself according to the figure correct, that is to say, that they arrive at the result of .5 meters or its equivalents (half a meter, 168 Most of the students interpret the problem as a situation in which built and how well consolidated and structured they are. solve the problem autonomously, unlike the results in the phase proportionality is involved. Which means that in the schematics of these chapter IV. do and this depends on the situation you are facing and the schemes you have without the intervention of the interviewer. Half of the students interviewed achieved VI.1.1.2 CORRECT AND AUTONOMOUS RESOLUTION Machine Translated by Google Table 14. Issues related to the Division Algorithm category 169 of the students did it, it means that although it is a fifth, it indicates that the related to the division algorithm. verification of their result without being requested by the interviewer. only 20% could use in their resolution process. This depends on the criteria An important part of the problem solving process is related to the verification of the result is a resource that students have available and that teachers. to find the answer to the problem question. Only 6 of the 24 did it for of the students to carry out the clinical interviews were able to generate these rigor assumed, learned by the students and the criteria 80 demanded by the Division algorithm. Most of the students used it as a tool categories and will show some examples of student productions. divided ”in the mind.” For this reason, a section is dedicated to the analysis of the data. This category highlights those students who carry out some type of differences in results. Each of these will be described in detail in the corresponding sections. deduction and did not require the written algorithm, but it does not mean that they have not Percentage 63.3 Thematic 19 46.7 division Frequency Calculator, orality/writing 36.7 Algorithm of the Mathematical writing with alphabetic directionality Algorithm reading with alphabetic directionality 15 dividend greater than divisor 11 Algorithm mechanics 14 7 23.3 50.0 SAW. 1.1.3 AUTONOMOUS TEST VI.1.2 DIVISION ALGORITHM Machine Translated by Google VI.1.2.1 WRITING WITH DIRECTIONALITY OF THE ALPHABETICAL SYSTEM The way to graphically represent the division algorithm was observed and the will operate and the referent of the result. found that 36.7% of the students (11 cases) did so following the rules of the representing 35 between 70 represents 70/35 in the conventional system. more than a third must be considered, because it determines the relationships between the magnitudes with which students by representing the algorithm (including with the calculator) and its interpretation the glottic writing that they dominate, in terms of Harris (1999). they put in 170 That is why in this section we analyze the graphic productions of the alphabetic writing system, that is, they wrote a script strongly influenced by with the rules of the division; and explore the ideas that students This is a very broad subject because it is not only related to the ”steps” To represent in writing what is verbally (writting and reading); the way to solve it (mechanics of the algorithm), which has to do correspondence between orality and writing and recover the directionality from left to right of alphabetic writing9 . interpretation because it is a graphic resource. In addition, each of its components division. while they are speaking it, 35 the galley of the division for “between” and 70. So instead of is related to an arithmetic meaning and its organization in graphic space to divide, but their written production and their build on the way to organize the data within the written algorithm of the express: ”35 out of 70”, for example, they write from left to right, even some 9 A similar case and that serves to better explain what we mean by the expression ”strong influence of glottal writing” we have verified in children who we ask them to write large amounts that they do not know how to write conventionally. Some children clearly match numbers or groups of numbers with fragments of the name of the number to be written. For example, the number three hundred forty-five represents it, even with self-dictation, ”three hundred” 300 ”forty” 40 and ”five” 5. The result is 300405. This procedure has been confirmed by other researchers (Sinclair, A. 1988; Pontecorvo, C. 1985). Children match elements of the graphic number system (which can be considered ”ideographic” or, more precisely, logographic, with words or word segments that form the name of the number). Machine Translated by Google Image 51. Mathematical writing with alphabetic directionality link with the alphabetic writing system that should be made independent. The questions 171 usable to solve proportionality problems. 81 algorithm written at some point in the interview, which again reflects a that arise are: when will they become independent?, what is required for that to happen? There is elements (35, ”between”, 70) and therefore the writing is conventional. of the 7 use the algorithm properly even when they recognize it as a tool In the same way, when they are asked to read the division they made, they do so Reading with directionality of the alphabetic system Remember that they are sixth graders and third graders of secondary school. of the alphabetical system, “35 between 70”. part of the students interviewed follows this algorithm writing procedure, calculator to solve the problem. If we take into account that typing the data in the left to right. For example, in the following image it would be read, with the directionality Within this group, the cases were also considered in which a of mathematical notation, each with different properties and purposes. It is a fact Half of the students interviewed made this type of interpretation of the alphabetic and mathematical writing disappears. They type in the order in which the words are listed. very important to consider, since it constitutes an obstacle that prevents students from which means that they have not succeeded in making alphabetic writing systems independent from the calculator is somewhat similar to writing them, so this difference between VI 1.2.2 CALCULATOR, SPEAKING/ WRITING Machine Translated by Google VI.1.2.3 MECHANICS OF THE ALGORITHM VI.1.2.4 DIVIDEND GREATER THAN THE DIVIDER division. technique as a sequence of steps, sometimes meaningless, these can be forgotten or unusually frequent its application to the graphical algorithm of the division. difficulties to reconstruct the steps or even recognize that they do not remember how to do the A part of these difficulties is linked to the fact of not knowing by heart the accommodate the data in graphic space. Since many students learned the influencing the tendency towards arithmetic writing with alphabetical direction, since it is In relation to the Mechanics of the usual algorithm of the division, by columns, it is analyzed calculate ”how much does 25 between 4” have to use ”the table of 4” but, if you don’t have changed. To make sense of both this arithmetic operation and the rest of the 172 multiplication tables, which makes the numerical estimation required by the algorithm difficult: for operations, they create theorems-in-act that guide the rules of action of their lead to calculation errors. students who used the calculator in the interview, all expressed a achievement of submissions, etc. the mastery of the students of the steps to follow and when they modify them giving from it, the estimate is costly and tends to distract the flow of reasoning, the negatively on the result. 46.75) adequately apply the usual algorithm technique. the other half have One of the difficulties encountered with respect to the usual division algorithm is how The use of the calculator to solve mathematical problems could be term-to-term correspondence between speaking and typing, without this having any repercussions The results show that slightly less than half of the students (N=14, Machine Translated by Google 173 than the divisor”, and for those who abide by this rule, the accommodation of the data of the rule at the time of writing down the division at least once. activity to solve them. One such theorem is “that the dividend is always greater division is not 82 a problem. The results indicate that 63% of the interviewed students applied this Machine Translated by Google Percentage Units Frequency 36.7 Thematic 11 13.3 Autonomous drive allocation Carrying the decimal fraction to unity 4 Table 15. Issues related to the Units item VI.1.3 UNITS product of arithmetic calculation. A recurring theme in clinical interviews is the assignment of units of measurement to the numerical results obtained by the students through some operation. result. The rest, almost two thirds, were satisfied with the numerical result, autonomous allocation of units and what we call “the carry of the fraction divide 35 by 70, either in writing or with the calculator, you obtain the quotient Although it is a very broad subject, for this section only two aspects will be analyzed: the Regarding the carry of the decimal fraction, it can be mentioned that it occurs when at They located 15 cases in which they added ”cm” as a unit of measurement. in the phase of decimal number, they interpret that being a fraction, the unit of measurement must also decimal to the unit”, that is, that some students when finding as a result a 0.5 and must assign the corresponding unit of measure. In the experimental phase, 36.7% of the students assigned a unit of measurement as part of the 174 change. clinical interviews also found 4 cases. One of them is Emiliano: VI.1.3.1 AUTONOMOUS UNIT ASSIGNMENT VI.1.3.2 CARRYING THE DECIMAL FRACTION TO THE UNIT Machine Translated by Google of the students with a similar answer, is the theorem-in-act “as the result is not It will be millimeters here, cent.... I just got confused. Well, now (2P) millimeters now The explanation that Emiliano gives, and that may be the same idea that the rest have an integer, then neither can the unit of measurement be”; therefore 175 (Write ml next to your answer, “0.5”) [Why did you hesitate? You were going to say [Umhoo] [You were going to put centimeters but you said no. Because... since it’s not integer, so It may be that later they will reflect on the real impossibility of taking half a step [Millimeters?] (1P, 9:31) millimeters [Can’t it be centimeters?] Pus maybe yes They are looking for a fraction of a meter: centimeters or millimeters. millimeters?] Half a centimeter [Like where to where is it from?] Over here [Mmm... so point five what is it?, how long is this?, what did you say?] means 0.5 centimeters or 0.5 millimeters, difficulty is also related to the you said?] Uh huh [So it’s millimeters] (Nods) [What is point five millimeter (what we call empirical feasibility) or even that they do not identify what Just spelled). Here, zero point five, what would be the measurement] Well, centimeters... how much? Point five millimeters?] No, I don’t know... I wouldn’t measure the step like that. situations are described below. no, millimeters [Millimeters? Let’s see, then put millimeters] To this one [Yes... there] Fifty centimeters [This... let’s see, write it down, if not, I forget (3P)] (Write 50 cm) [Come on, here you are putting a number and the measurement (indicating what you (points) [Would that be... a centimeter?] One centimeter [Then your step measures, level of construction of the concept of rational number (Charles, 2011). Both Machine Translated by Google Percentage Result Frequency 70.0 Thematic 21 66.7 Relationship between the symbolic-concrete planes Empirical 20 feasibility Table 16. Issues related to the category Result VI.1.4 RESULT VI.1.4.1 RELATIONSHIP BETWEEN THE 83 SYMBOLIC PLANE AND THE CONCRETE PLANE students (N=21) were able to correctly identify the measurement on a specific plane concrete and symbolic representation, and the empirical feasibility of the result. In it First, the type of relationship that students conceptualize between the Regarding the result, two elements stand out: the relationship between the planes of a ruler or tape measure the segment that represents the result obtained. 70% of the second, if they consider that their result is possible in the real world, for example that [This... from where to where is half a meter?] From... [If you could point to me] Maybe represented on the symbolic level. For example, Gustavo is clear about the distance graphical representation of the result and its correspondence with the concrete plane. In it approximately half a meter and you can also accurately locate it on a measuring tape. both hands on one end of the table, then measure it and the difference is someone can take steps of 2 meters. This piece is half meter (approximate size to half meter showing with centimeters (or two meters, 2 cm, depending on their answers)”, or they are asked to point to 176 Regardless of their result, they are asked “from where to where are 50 minimum, between 5 and 10 centimeters.) Machine Translated by Google Image 52. Gesture to indicate the size of a step. (pointing vaguely) [From the table to here, how much is it?] Like a meter and 177 In other cases, there is no clarity about the specific distance that the result represents. like how far, can you tell me with your hands?] Like from there to here medium [But thirty centimeters?] From to... from this table to the other table [From here from wonder why. If we take into account that the youngest students This... if you take two steps of half a meter, how far do you go?] One meter. centimeters is equal to the distance between two poles (tubes that support a roof on the (pointing approx. 2 meters), yes? Eh... you, how big do you take your steps?] I don’t know obtained. For example, Carlos, a sixth grader in an urban primary school, mentions that 30 my finger or from here to there] From here to there [Is this to there a foot? Alright, can you imagine this... well, about how much is that, a foot, bigger than from here to there] (Nods) [Oh, little by little, really? (laughs). schoolyard with an approximate distance of 3 meters between them): [How much do you imagine?] Fifty [Fifty? So your steps are gives a tape measure)] (Measures a segment of the table, points to the fifty post [A light post?] No, the ones that are out there [Ah... I didn’t see, representation. However, a third do not do so, which is why it is important centimeters) Here [There. Can you take half-meter steps?] Yes [Yes, right? [Yes? How do you know?] (1F) [Eh?] Calculating it [Calculating it, let’s see, with this one (he From where to where will it be?] From... from... (Looks around the room). From one post there to another Most of the students establish the homomorphism between both planes of Machine Translated by Google that is not bad, nor is it good] Umju [Isn’t it bad?] No, it’s good, I don’t know why inch?] Mmm... three... mmm... about three... centimeters, something like that [Three?] Three Regarding empirical feasibility, most students also take into account 2 cm) [What do you think of your answer?] Hmm... regular? [regular, means you guys [Hmm... do you know the tape measure?] Umhoo [Here on the tape measure? the tape) [Are you going to 84 show me two inches?] Umhoo [Like how long is a (66.7%, N=20). Only in 10 cases do they not do so, despite obtaining steps of time, point it to me here] (Point to 20 cm) Here [There, is this... here would be two? point... [Point eight] Eight [Hmm... I think these are inches right?] conflict that the step size is that size maybe because you have not lent consideration the real possibility of the size of the steps that they obtain as a result where would you place the result it gave you?] Mmm... (Points) [Here?] Umhoo [Another Javier considers that Hector’s step is 2 centimeters, it does not cause him any For example, Javier, sixth grader at an urban elementary school: They are in sixth grade and that for this educational level the use of measuring instruments, That would be two inches, right? [Two inches?] Two inches [Mmm...] (Strike out cm in 2 meters, 2 centimeters or 0.5 cm. centimeters?] No... two centimeters (apparently he corrects pointing) [Ah...] Those 178 It is important to point this out and keep an eye on the progression of mathematical knowledge steps would be two centimeters? [Yeah. What you believe] (Write as answer inches [Two inches] Well, it gives me like uh... here (points to between 12 and 13 cm in elementals mainly for magnitudes of length it must be a content already mastered, that is [Yeah. And what would be the answer?] Two? [Two what] Two... ah... the size of the your answer and write inches). Can I write with a pencil? Well give inches, two VI.1.4.2 EMPIRICAL FEASIBILITY Machine Translated by Google inches. It is once again a ”diffuse” or lax conceptualization of the results, We believe that the first interpretation is more likely because it is something that distance cannot measure two centimeters, so it resorts to another unit of measurement; the or of mathematics in general, conceiving that a result may be right for (points). real possibility, or that he does not know how to indicate the amount of 2 cm on the measuring tape. obtained, for example with the arbitrary use of the decimal point by means of rules for you”. [Umjú] And the other would be here (with the arms in the same position, he places them to the we have been observing other students when they make “adjustments” to the results some and bad for others, as expressed through his statement: “no, it’s good. I don’t know 179 close to what is empirically possible. Another fact that allows us to affirm this inference is pay attention to its meaning. When asked to show on a tape measure, you do not point two meters and is clear about the distance it represents. external to the numbering system or measurement system so that its result is more On the other hand, Irene, from the urban secondary school, considers that it is possible to take steps centimeters. It can mean either that by becoming aware of the size that they represent Because you made the adjustment to make the length longer and you know that a lot?] I think so [How far is two meters?] Well, I don’t know, one meter would be like this 2 centimeters he wanted to arbitrarily adjust the length to correspond to a properly the point where it is located, but rather indicates the position of the 20 the change that Javier makes to the unit of measurement, going from centimeters to inches. [Yes, it can be like that?... So what will it be?] Well, two meters is a lot [What, is it Image 53. Shows the approximate distance of one meter. Machine Translated by Google take steps so small or so big. However, what these results show is This case is similar to the previous one in 85 that it considers that it is possible to take steps according to different plans and there are also few who do not consider the real feasibility of that a more systematic didactic work is required that considers various planes of considers that it establishes the appropriate correspondence between the symbolic plane and the corresponding, without neglecting the idea that mathematics should serve to result obtained, in this case 2 meters. But the difference is that Irene representation in which students can build relationships depending on the size of the person. The fit does not do so in mathematical terms, left of the marked segment to indicate another step) [can you take a step some references to reflect on their results. concrete and still considers it empirically feasible to take steps of that size real issues, at least in basic education, so that students have [And which one convinces you more, two centimeters or two meters?] Two meters [Yes? Well There are few students who fail to establish the homomorphism between the write it] (Write “2m”) [Very good]. like this?] Well... yes, it depends on the person, if he is very big, well he can give them but what adjusts to the result is reality. 180 Image 54. Shows the approximate distance of two meters. Machine Translated by Google VI.2 CONCLUSIONS OF THE CHAPTER interprets it in the same way, that is, it reads it from left to right. students (almost two thirds) do not consider it necessary to specify the we can rescue is that there are those who spontaneously make a verification (20%) students write the algorithm with an alphabetical directionality and half of them write it Based on the above, we consider that beyond the old discussions about Regarding the units, these results show that the majority of the problem, in addition to the fact that the application conditions are very different. what yes with the rigor of learned mathematics. ourselves, we must overcome that stage in the didactics of mathematics and give it the value reference units to your numerical result. Again this data makes us students as well as their teachers. Is the matter of the units an issue that should be but most do not; We consider that it is a resource that is related teach algorithms or not because of the mechanical and thoughtless application of the reflect on the epistemological conception they have of mathematics, both as a tool to find the result, but only half use it both in its conceptual and procedural part, it allows students to reflect 181 On the other hand, most of the students resorted to the division algorithm They have support for problem solving. The domain of algorithms, teach as such? or when taking into account the rigor of the approaches problem and autonomously, unlike the results of the experimental phase, Another important fact to highlight is that more than a third of the and allows them to outsource their concepts. We must remember that this is the second time these students have solved the same problem. Although these data show that half of the students correctly solve the properly; the other half have difficulty using it or even remembering it. about the mathematical concepts involved, the relationships between the data in the problem Machine Translated by Google 20% of students fail to adequately establish this relationship. Therefore it is The carry of the fraction from the numerical unit to the unit of measurement is a sample of rendering plans. In this problem the relationships seem somewhat trivial, but the It is advisable not to lose sight in the didactic work of these 86 correspondences concepts, requires building over time and through multiple situations. as was seen in the topic of measurements in the theoretical chapter, it has taken centuries in the major, with the study of algebra for example. the cognitive activity of the students to try to understand these notions that, between the different planes, since in later educational levels the complexity will be Another point that is important to highlight is that most of the students Mathematicians should not consider the possibility of giving only the numerical result without study of mathematics understand them. 182 The above regarding the conception of mathematics, but with respect to the results obtained. This relationship, Vergnaud suggests, should be monitored between the different construction of knowledge, the definition of measures is an issue that, like all specify the unit of measure. establishes an adequate relationship between the symbolic plane and the concrete plane in the Machine Translated by Google CONCLUSIONS that they have the ability to learn and apply mathematical knowledge and that if Therefore, representation systems play a very important role in Based on the results obtained, it is possible to show that the students of while solving a mathematical task in interaction with a mediator. Means experience difficulties, these are mainly related to the lack of representation. multiplicative structures. problems that arise in school contexts, build knowledge through representation systems. conceptualization processes, but we do not mean by this that knowledge language. As we were able to show, most students are proficient in mathematics. basic education use their mathematical knowledge to face situations consolidation of said knowledge at a predicative level, that is, externalized to is built only from the mastery of these systems, for example only through the concepts and theorems-in-act to make sense of a new situation. representation systems and the consolidation of mathematical concepts. When there is 183 during the interaction with mathematical objects through the formulation of The data also show that there is a close relationship between mastery of in its operative form, but they face difficulties in the predicative form. writing, language, and mathematical conceptualization through the study of capable of reasoning, of mobilizing their mathematical knowledge and of constructing new very lax or “liquid” (as Zygmunt Bauman would say) the rules of the systems of process of solving a mathematical problem in the conceptual field of With this work we deepen the understanding of the relationship between the The students who were part of this study also showed that they are a loosely constructed, fuzzy conceptualization, students apply Machine Translated by Google results obtained. necessary. In this regard, we consider that the understanding of algorithms, their domain and interaction (in this case with the interviewer and with knowledge), language and writing In other words, most of the difficulties that students their correspondences between them. This does not mean that mastering the systems of problematic and from this they were able to identify its invariances, very important role in the basic education curriculum; have gone from being understanding of several interrelated concepts and various levels of complexity: the some of its properties and relationships with other objects. But this language is protagonists in the didactics of mathematics to practically play 87 the antagonistic role. 184 iceberg whose base, generally invisible, consists of the conceptualization must be re-constructed by students to use them properly and take the tool that most students, both elementary and secondary, do not time. allows to maintain control of the activity during the resolution process, which supports consequence of the insistence of educators and specialists not to teach working memory and that allows to adequately communicate the procedures and algorithms and has been taken to the other extreme, not giving them the importance The results obtained in this investigation also indicate that, during the the possibility of using their respective graphic representations also implies the they faced are related to the lack of mastery of the systems of representation and helped students recognize the objects involved in the situation On the other hand, with respect to the algorithms, we consider that they have been given a representation students will consequently master mathematical concepts. Vergnaud has been very clear in describing symbolization as the tip of the great organized into systems and each system has its own rules and conventions that From this research we can conclude, about algorithms, that they are a constructed through interaction with multiple situations over long periods of time function of a tool that supports reasoning, that favors reflection, that dominate according to what is expected for this educational level. Possibly this is a Machine Translated by Google decontextualized teaching. The same happens with multiplication tables, which to know in advance the difficulties that students face in order to be able to more abstract mathematical content such as algebra. Instead, the flimsy numbering system, measures and composition of measures, units of measure, etc Therefore, not only is mastery of the ”mechanics” of the algorithm required, but also find themselves helpless before problems that we could even consider trivial. The as if that meant something anti-pedagogical, they can guide students to activities or their interventions. solving the algorithm can become, as we have already seen, a more complicated task consume time and processing to deduce that information, from which they should be able to 185 The domain of written algorithms of elementary arithmetic includes both its The 2009 primary study plan and programs recognize the importance of In relation to the learning process, the modification of meanings, powerful tools to confront a wide variety of problems, both school However, in practice (in the classroom) it seems that something else happens. It’s important to give them interviewer and student. The problematic situation demands the application of the the importance they have, without this meaning a thoughtless return to the past with their corresponding schemes; the teacher must master the problematized content and as non-schoolers, and it is also of great importance for the understanding of differentiate conceptual errors from local misunderstandings and in this way guide the decimal numbers, rational numbers, proportionality, ratio, fraction, comprehension and consequently its failed application make students some teachers in order to prevent students from learning them ”by heart”, also its teaching is an opportunity to reflect on the concepts involved in the operation carried out. than the problem it is supposed to solve. have it ”automatically”, to be able to use it in the resolution procedures. graphic representation as well 88 as its interpretation, makes these become teaching algorithms in the context of problem solving. Without revealed by microgenetic analysis, occurred in interaction with both knowledge, Machine Translated by Google the students generated and that at the same time prevented them from being able to solve training in mathematics and didactics of mathematics would favor the identification The teacher therefore has the responsibility to train himself to master with Vergnaud considers that one of Piaget’s fundamental inheritances to that students build knowledge through activity about objects and face the didactics of the different disciplines but in particular the didactics of the situation, that is, by identifying the characteristics of the problem, the resources to guide teaching activities and thus promote their improvement. math. It is required that they know the mathematical contents that that requires for its solution, the possible difficulties that could represent for the 186 proving his theorems-in-act through multiple situations, where contents, that is, the most efficient way in which they can guide the activity research like this and with individual clinical interviews with a few students. to improve or replace said theorems, reorganize their schemes, combine them or knowledge expected from educational institutions. daily mathematical content but also the content of other disciplines In the cases we have analyzed, we were able to unveil some theorems-in-act that many students (on average 40 students per group). However, a good generate new ones. of students’ difficulties, would allow teachers to take advantage of their mistakes education was to consider activity as the origin of knowledge. Means sufficient depth the contents that it intends to teach. This has been a challenge appropriately for that specific situation. However, this was achieved thanks to the analysis the situations. Therefore, if we want to take advantage of this heritage, it is important that the teachers encourage students to act on reality, experimenting and will be taught to the students and also that they know the didactics of said students and ways to get around them. Of course this happens in a job They will invariably make mistakes that at the same time become opportunities. of the students to face didactic situations to ensure that they build the The reality of Mexican teachers is very different, because they must not only teach Machine Translated by Google notion of the decimal point and the different uses and meanings of its representation Although the data obtained do not show significant differences with respect to the this second aspect of work has been ignored in the didactics developed in Mexico The didactics of mathematics in basic education in Mexico has been oriented curricular contents (Secretary of Public Education, 2012). It has focused more on From this work, veins of research are opened on the relationship between the didactic interest and should be explored in depth considering both the construction of a broader exploration of the variety of problems where one can highlight symbolic systems of representation and mathematical concepts. required now of the notion as the evolution of representation systems. What was not achieved 187 Knowledge is the product of the subject’s adaptation to the situations faced. In different planes of representation through the analysis of the classes of situations that concepts involved, particularly that of rational numbers. This topic is located 89 by the teachers, both in the design of the didactic situations and in the analysis problems belonging to the conceptual fields involved. tangentially in the clinical interviews and in the analyzes and interpretations of the Some of the issues that we highlight in this research are: the evolution of same. of the schemes that students evoke and use to face them. We consider that use of the calculator, we consider that it is necessary to deepen the matter through to the development, revision and reconstruction of didactic situations for the teaching of the and it is important to coordinate both perspectives. symbolic in different situations; The notion of measurement is another topic that is of great the object of teaching than in the cognitive processes of the subject. from the perspective theoretical and epistemological on which we base this research, it is conceived that the carry out research on the construction of mathematical concepts and their deepen, among other topics, was in the investigation of the domain of the different In this sense, the construction of knowledge should be favored by the consideration, give meaning to these concepts. For this it is necessary to explore a variety of as central to the difficulties faced by the students and explores Machine Translated by Google highly industrialized; the same happens in family contexts. According to but that came out” or ”it’s fine for me, I don’t know about you” or that ”they appear from the methodological design that is focused on exploring this aspect in depth, will be the advantages and disadvantages of this technological resource in the learning process of the Finally, we support the hypothesis that empirical feasibility is a referent and those of appropriation and use of basic mathematical tools to live in the century both its use, development, use and application will be different. Therefore, for their needs, shows that they conceive of mathematics as a school content XXI. that mathematics is valued and used as one would expect it to be, it is also 188 allow us to deal more regularly and freely with problems on a specific level It is important to take into account that mathematics is a cultural tool that is in which they live. contextual, they do so by emphasizing other planes of representation. Even though in assessment depends on the context of each student, family, school, locality, state or some of the conceptions that students have of mathematics regarding the country. They will not attribute the same value to it in a rural location as in a locality rigor and precision. Expressions like ”you can’t take steps that size our results the differences were not significant, we consider that with a nothing a decimal point” that they strategically place in the result to adjust it, according to solving mathematical problems. possible to know better and better the processes of acquisition of mathematical knowledge the configuration of the contexts is that a value will be given to this tool and therefore to which students from rural localities resort more, unlike what happens with students from urban localities, because the conditions in which they live On the other hand, we share the perspective of Gérard Vergnaud when considering that would require improving the living conditions of all people and improving localities first while the students of urban schools, due to their same conditions conforms of objects, procedures, demonstrations and that as a cultural object its Related to the above, this research also allowed us to identify Machine Translated by 90 Google contextual, idiosyncratic and cultural characteristics of those who use them. It is important to continue the regulations, red tape (there is always the possibility of ”arranging” to investigations to delve into these conceptions of both students and can be arbitrarily adjusted by the subject depending on their intuitions, Seems like a cultural trait: stats can be used with those too skip some steps). needs and expectations. motives, mainly those that try to show the achievements in the different types of teachers and be able to make didactic suggestions in this regard. Therefore, the conception of mathematics does not escape the aspects 189 government reports. The laws could have this same treatment, the flexible, partial and imprecise, that is, whose procedures, components and results Machine Translated by Google REFERENCES paris.fr/Corpus/AAR/FR/_video.asp?id=413&ress=1378&video=104279&format Bautier, E., Crinon, J., Rayou, P. & Rochex, J. (2010). Literacy performance, modes of high school students. The Day. 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Thought and language: a theory of the cultural development of the 200 psychic functions. Mexico: Quinto Sol Editions. Machine Translated by Google 10 CONCEPTUALS BY GERARD VERGNAUD. ANNEX 1. TRANSLATION OF FIELD THEORY Science is reduction. But not all reductions are fruitful. Today it is more or less accepted that Piaget provided a magnificent contribution to developmental psychology, when the behaviorists had not been able to do so. Despite this, he declined his work in the analysis of mathematical content due to his fascination with logic and his hope of being able to reduce the increasing complexity obtained by children to logical structures: for example, his analysis of the ”formal stage ” allowed him to identify the group of INRC transformations as the characteristic that could help to understand proportionality in children. In doing this, he did not pay enough attention to content that is specific to mathematics, namely, the properties of functions. Paris 8 University, Saint-Denis, France The theory of conceptual fields is a theory of development. It has two purposes. Human Development 2009; 52:83–94 Keywords THE THEORY OF CONCEPTUAL FIELDS10 DOI: 10.1159/000202727 (1) Describe and analyze the progressive complexity, in the medium and long term, of the mathematical skills that students develop inside and outside of school, and (2) establish better connections between the operational form of knowledge, which consists of acting in the physical and social world, and the predicative form of knowledge, which consists of the linguistic and symbolic expressions of this knowledge. As it deals with the progressive complexity of knowledge, the framework of the conceptual field is also useful to help teachers organize didactic situations and interventions, according to the epistemology of mathematics and a better understanding of the conceptualization process of students. Conceptual fields, Theory of development, Progressive complexity of knowledge Introduction Gérard Vergnaud 201 94 Summary Translation made by Alfonso Javier Bustamante Santos, November 2011, revised by Jorge Vaca and Veronica Aguilar Machine Translated by Google From this starting point, several questions arise: First I will emphasize the importance of activity, schemas, and situations for psychology, and then I present a definition of a conceptual field as the set of situations and concepts. The concept of schema also requires some attention, because it plays a crucial role in the analysis of the operational form of knowledge, as distinct from the predicative form. Finally, I will try to discuss different and complementary aspects of the concept of representation. 1. Is it possible to theorize about reasoning with the concept of schema, and specifically about mathematical reasoning? ÿ the isomorphic properties of linear functions: the constant coefficient f(x) = kx The concept of schema f(x + y) = f(x) + f(y) y f(ax) = af(x) A double proportion is when one variable is proportional to two other independent variables. So the properties of bilinear functions are relevant. 2. What is the role of schemas in the functioning of representation? Why and how are they components of the representation? The concept of schema was not introduced by Piaget: several 19th century philosophers mentioned it after Kant introduced it and it was also used by various psychologists during the first decades of the 20th century, notably Revault d’Allonnes (eg 1915, 1920) and Janet (eg 1928) in France. However, Piaget was the first to provide concrete and compelling examples of its meaning with his descriptions of early development in infants and young children. His book La naissannce de l’intelligence chez l’enfant (”The birth of intelligence in the child”, Piaget, 1968a) is not only the ”invention” of the cognitive development of the child as a new field of research, but also the demonstration that gestures and perceptual acts are the empirical basis for their analyses. Therefore, the sequential organization of activity for a certain situation is the primitive and prototypical reference for the concept of schema. 202 These properties could have better described the different emerging skills in a few years: the recognition and analysis of products and ratios of dimensions as is the case for relationships between length, area and volume, or between measurements in physics (for more details, see Vergnaud , 1983). However, in the theory of conceptual fields, I borrow from Piaget other important aspects of his work: first, the concept of schema, to which I give a broader interpretation than his; the thesis that knowledge is adaptation (accommodation and assimilation); as well as the general Piagetian conception that action and representation play the main role in development. The simple proportion is a function of one variable; and two types of properties are essential: Machine Translated by Google 203 How is this theory related to the development of mathematical knowledge? Activity, schemes and situations Therefore, the schema/situation pair is conceptually more interesting and powerful than the response/stimulus pair, and it is also more feasible to describe and analyze behavior and representation using the schema/situation pair than the subject/object pair. Do we have some examples of schematics in mathematics? The theory that knowledge is an adaptive process is essential, but what is adapting and to what? To date, the most reasonable answer is that what adapts are the forms of organization of the activity, the schemes, and 95 they adapt to the situations. If the first reference for schemata is what Piaget (and most psychologists in the early 20th century) called ”sensory-motor” activity, the first theoretical question to ask is how gestural and perceptual actions performed in the world real are or become internal resources. It is not enough to say that schematics are found in neurons and genes, because it is impossible to try to describe the organization of a single schematic as an organized sequence of active neurons, or as a configuration of genes, due to the trillions of elements. involved. The first example I will give is the scheme of counting objects. When children are able to count a small set of objects, they use three different repertoires of gestures: arm and finger movements, eye movements, and words. The effectiveness of the scheme depends on the one-to-one correspondence between these three activities and with the set of objects in the physical world. It also depends on the ability to conclude the episode by naming the cardinal of the set, which is more than the last element of the set: the cardinals can be added while the last elements cannot. The concept of number is characterized by the additive property of cardinals, a property that equivalence and order relations do not have. The concept of cardinal is implicit in the child’s activity: it is a concept-in-act. Furthermore, this biological description ignores the critical point of relating the external and internal parts of the activity, which is an essential point in promoting an integrated psychological framework. The most fruitful idea I can find is that of internalization (or internalization) of activity, both Piagetian and Vygotskian. This idea is well developed in Piaget’s (1968b) book La formation du symbole chez l’enfant and in the first chapter of Vygotsky’s Thought and Language (1962). The paradox is that, in his radical critique of the Piagetian ”egocentric feature” of infant language, Vygotsky develops the idea that egocentrism is rather ”a step in the process of internalizing” dialogues, and offers the very idea of ” internalized imitation” that Piaget understands as one of the first processes of representation. 3. What is its relationship with other components such as concepts, linguistic entities and symbols? Machine Translated by Google 204 In the first case, the binary combination of two parts into a whole, only two kinds of problems can be generated: knowing the two parts, find the whole, and knowing the whole and one of the parts, find the other part. What is a conceptual field? Because schemata and situations are the roots of cognitive development, and because concepts-in-act are essential parts of schemata (see definition below), the development of a conceptual domain requires children to know about and deal with contrasting situations. Researchers also need to carefully analyze the different ways in which children deal with them. In this paper, I will give only one example, the conceptual field of additive structures. However, there are other good examples, such as multiplicative structures, the geometry of figures, positions and transformations, and elementary algebra. In the second case, six classes of problems can be created: knowing the initial state and the transformation, find the final state (by increasing or decreasing the initial quantity); Knowing the initial and final state, find the transformation, when the final state is greater or less than the initial state; Knowing the final state and the transformation, find the initial state by increasing or decreasing 96 the final state. Of these six kinds of situations, four require subtraction and only two require addition. Addition and subtraction are not just inverses of each other. It is at the same time a set of situations and a set of concepts linked together. By this I mean that the meaning of a concept does not come from a single situation but from a variety of situations and that, reciprocally, a situation cannot be analyzed with a single concept, but rather with several, forming systems. There are two prototypical situations for addition: the binary combination of two parts into a whole (”4 boys and 5 girls are on Kath’s birthday, how many in all?”) and the increment of an initial state (”Richard had 4 marbles, you won 5; how many marbles do you have now?”) which can best be modeled by a unit operation, a function from the set of possible initial states to the set of final states. There are wide and significant differences in the success or failure achieved by children when dealing with the different kinds of problems that can be generated from The distinction between these two prototypes becomes clear when one considers the variety of problems that can be generated. Another early example of a schema in mathematics is the perceptual activity used to recognize a construction or figure as symmetrical. Examining symmetry may be more sophisticated than what 10-year-olds are capable of (for example, they may not check for equality of angles or even equality of distances with the axis of symmetry). But even when control is lost, some invariant properties of symmetry are considered: these are also concepts in action. Machine Translated by Google -1 Fig. 1. Sagittal diagram. where I is the initial state, F the final state, T the forward transformation, and T the inverse transformation. This theorem can also be represented by a sagittal diagram (fig. 1). The simplest addition and subtraction situations can be solved by some 4-year-olds, yet some situations requiring only one addition are not solved by most 13- or 14-year-olds: “Robert played two games of marbles; he remembers that he lost 7 marbles in the second game, but he doesn’t remember what happened in the first. When he counts his marbles at the end, he realizes that he won a total of 5 marbles. There are not only contrasts between situations, but also between schemes, ie, between ways of dealing with situations. There are of course wrong ways, but one can also observe different useful schemes for the same kind of situations, depending for example on the numerical values of the variables. Some children can of course subtract 7 from 11, others can count backwards from 11 to 7 and then count the number of digits, others can count from 7 forward to 11, and still others can even make a hypothesis about from the initial state (5, for example), apply the increment of 7 marbles, find 12, which is very large, and then correct your hypothesis. This last scheme is mainly due to the conceptual difficulty of reversing the increment of 7, by applying a subtraction of 7 to the final state. This operation of thought requires a theorem-in-act: What happened in the first game? Let’s take the following situation: “John just won 7 marbles playing with Meredith. These two symbolic representations (the algebraic and the diagram) show that there are also contrasts between the ways of symbolizing objects and their relationships. undoubtedly the If T(I) = F then I = T-1 (F) 205 Now he has 11 marbles. How many marbles did he have before playing?” these two 97 prototypes and the other cases such as the quantified comparison of quantities (“Who has more and how much more? Find the compared or the referred quantity”), or also the combination and decomposition of transformations. Machine Translated by Google be developed into subgoals and anticipations. The operational form of knowledge - The generative aspect of the schemes involves rules to generate the activity, specifically the sequence of actions, the collection of information and the controls. - You lose what you have won; or win what you have lost. - You return to someone the amount they gave you or you recover from someone the amount of money that you lent them. A debt is therefore the inverse of a balance in favor. Researchers dealing with the development of mathematical skills cannot be satisfied with the idea that mathematical words and sentences, as they appear in textbooks or in teachers’ comments and explanations, can be a sufficient criterion for assessing student competencies. Testing their activity in situation is essential, particularly in new situations, when they have to adapt their cognitive resources and face a problem never before known. The function of the schemas, in the present theory, is both to describe the ordinary ways of doing for already mastered situations and to give clues on how to deal with new situations. Schemas are adaptable resources: they assimilate new situations by adjusting to them. Therefore, the schema definition must contain pre-made rules, tricks, and procedures that have been shaped by situations already mastered; but these components should also offer the possibility of adapting to new situations. On the one hand, a schema is the invariant organization of activity for a certain class of situations; on the other hand, this analytical definition must contain open concepts and possibilities of inference. From these considerations it is clear that schemes comprise several aspects, defined as follows: - You go back as many steps as you have advanced and vice versa. Not only are increase and decrease, or movements back and forth, the empirical roots of positive and negative numbers, but also the relationships between two people (lender and debtor) are examples of positive and negative numbers. This is important for teaching algebra and accounting. 206 - The intentional aspect of the schemes involves one or several goals that can be A tentative conclusion is that the development of a conceptual field involves situations, schemata, and symbolic tools of representation. A comprehensive definition of representation is required, but I will get to it only in the conclusion of this paper. Algebraic representation may not be useful for children at the elementary level while the sagittal diagram may at least carry the meaning of going back and forth. This is essential, but it doesn’t solve the problem of understanding that +7 and -7 are inverses of each other. Children need several examples of the inverse character of the addition and subtraction operation. Several types of awareness are needed: Machine Translated by Google The following example, in the domain of multiplicative structures, shows the difference very clearly: “suppose a student needs to find the amount of flour that he can make with the corn production of a large farm: 182 t. He knows that it takes 1.2 kg of corn to make 1 kg of flour.” The scheme that comes to mind after some time (meaning it’s not a simple idea) is to try to find the ratio between 182 t and 98 1.2 kg. This ratio is a scalar, a number that does not refer to a dimension, since it is the quotient of two magnitudes of the same type (amounts of corn). But the choice to calculate that ratio comes from the idea that it can be used to find the corresponding amount of flour: it is the same - The computational aspect involves possibilities of inference. They are essential to understand that thought is made up of intense computational activity, even in seemingly simple situations, and even more so in novel situations. We need to generate goals, subgoals, and rules, as well as properties and relationships that are not observable. The dialectical relationship between situations and schemas is so intricate that sometimes an expression relative to situations is used to refer to a schema, for example high jump or solving equations with two unknowns, as well as expressions relative to schemas to refer to situations, for example, rule of three situations (the rule of three is a scheme, not a situation). 207 The main points that I need to highlight in this definition are the generative property of schemas, and the fact that they contain conceptual components, without which they would be unable to adapt the activity to the variety of cases usually faced by the subject. I also feel the need to add several comments on the following. Another clarification concerns the relationship between concepts and theorems: the link is so intricate that many researchers tend to confuse them. The difference is that a theorem can be true or false, because it is a statement (or a proposition). A concept is not a statement and therefore cannot be true or false, but only relevant or irrelevant. Another important point is that a statement can be thought to be true when in fact it is false, it is still a theorem-in-act. There is little difference, from the point of view of the activity, between a true proposition and a false one that is considered true. The relationship between theorems and concepts is dialectical, in the sense that there is no theorem without concepts, and there is no concept without theorems. But the distinction is important for conceptual field theory, because it is a developmental theory. For example, the analysis of additive structures shows that the concepts of addition and subtraction are developed over a long period of time, through situations that evoke theorems of very different levels. - The epistemic aspect of schemes involves operational invariants, specifically concepts-in-act and theorems-in-act. Its main function is to collect and select relevant information and infer goals and rules from it. Machine Translated by Google 208 The operative form and the predicative form of knowledge F (rate X 1.2 kg) = rate XF (1.2 kg) The calculation also requires a change of units, from tons to kilograms. The problem could be simplified if the farm production were given in kilograms, but it is not usual to do that for large productions. Complexity not only comes from doing, but also from putting something into words and saying it. This theorem is completely implicit and the process requires, also implicitly, that F (182 tons) be identified as F (ratio X 1.2 kg), and that F (1.2 kg) be identified with 1 kg of flour. The scalar ratio between 182 tons and 1.2 kilograms is a concept-in-act, not a theorem-in-act, but its use is invoked by the theorem. Enunciation plays an essential part in the conceptualization process. One of the difficulties that students encounter when learning mathematics is that some mathematical statements and symbolic 99 expressions are as complex as the situations and thought operations required to deal with them. Some researchers even consider the difficulty of mathematics to be primarily a linguistic difficulty. This idea is wrong because mathematics is not a language, but knowledge. The above scheme is not an algorithm, but it could be formalized into the following algorithm: ”in a four-term proportion, find the ratio between the two magnitudes referring to the same type of quantity, and then apply it to the other quantity”. It is one of the practical responsibilities of mathematicians to discover or invent algorithms and the job of students is to learn them. Algorithms are schemes, but not all schemes are algorithms. The reason for this is that schemes do not have all the characteristics of algorithms: they lack ”effectiveness”, namely the property of reaching a solution, if any, in a finite number of steps. However, the organization of the activity is very similar in terms of schemes and algorithms. This similarity includes the fact that the algorithms taught to students are often appropriated by them under a simplified organization; they may even switch, after some time, to wrong schemata. ratio between the two quantities of corn (182 t and 1.2 kg) and the corresponding two quantities of flour. Therefore, when you know the reason, all you have to do is multiply it by the amount of flour corresponding to 1.2 kg of corn: Machine Translated by Google However, understanding and verbalizing mathematical sentences plays a significant role in the difficulties encountered by students. To illustrate this point, let’s take two situations in which students have to draw the symmetrical figure of a given figure. These situations contrast with one another, both from the point of view of the schemata that are necessary for construction, and from the point of view of the statements that one has to understand or produce on these occasions (fig. 2). In the first case, there are some coordination difficulties because the child needs to draw a straight line just above the dotted line, not too high and not too low, and everyone knows that this is not easy with a ruler; It is the same type of difficulty for the starting point and the arrival point. There are also conditional rules. For example, “one square to the left in the part already drawn, one square to the right in the part to be drawn”, or also “two squares down in the figure on the left, two squares down in the one on the left”. right”, or “one square to the right in the left figure, one square to the left in the right figure”, starting from a reference point homologous to the starting point on the left. Fig. 2. Two situations for symmetry The first figure corresponds to the appropriate situation to be presented to students aged 8 to 10, in which they must complete the drawing of the fortress symmetrically to the vertical axis. The second situation might typically be presented to 12- to 14-yearold students in France: construct a triangle symmetrical to triangle ABC in relation to d (“d” here refers to the dotted line). These rules are not very complex. However, they depend on various concepts-in-act and theorems-in-act concerning symmetry and the conservation of lengths and angles. Since all the angles are right and the lengths are expressed in discrete units (squares), the difficulty is minimal. In the second case, drawing triangle A’B’C’, symmetrical to triangle ABC in relation to line d, is much more complex with the usual instruments in the classroom (ruler, 100 compass and set of squares). Even the reduction of the triangle to its vertices 209 Machine Translated by Google S( A´B´C´, ABC,d) Triangle A´B´C´ is symmetrical to triangle ABC in relation to the Cl (s) y Ca (s) The fortress is symmetrical. Symmetry is an isometry. 210 Symmetry preserves lengths and angles. Between statement 1 and statement 2, there is already a qualitative leap: the symmetric adjective moves from the status of a one-element predicate to the status of a three-element predicate (A is symmetric to B relative to C). as sufficient elements to complete the task is an abstraction that some students do not readily accept because they see the figure as a non-decomposable whole. One step further, using the line d as the axis of symmetry for the segments AA´, BB´, CC´, is far from trivial. Why draw a circle with its center at A, and why should we be interested in the intersections of that circle with line d? line d. The epistemological leap from the first to the second situation is obvious. But there is also S(f) great leaps between the different statements that it is possible to articulate on these occasions.11 One can also use a set square and draw a perpendicular line from A to d, measure the distance from A to d, traverse the line d to construct A’ at the same distance from A to d. But how can I think that the distance is the same when there is no line yet? Between statement 2 and statement 3, the symmetrical predicate is transformed into an object of thought, symmetry, which has its specific properties: it preserves lengths and angles. Nominalization (ie, forming a name from another class of words or group of words) is the most common linguistic process used to transform predicates into objects. In statements 1 and 2, the idea of symmetry is a predicate (a propositional function); in statement 3, it was converted to an object (an argument). The lowercase “s” is the type of symbol used by logicians for arguments, while the uppercase “S” is used for predicates. The two new predicates, Cl (conservation of lengths) and Ca (conservation of angles), are thus properties of this new object s. The author uses French to show the definite articles that are not appreciated in English. Since this is possible in Spanish, we do the translation directly. 11 Machine Translated by Google 211 The different considerations and examples given above can be brought together to theorize about the concept of representation. Behaviorists wanted to get rid of that concept when they should have considered it a central concept of psychology, like the concepts of force and motion in mechanics, or those of evolution and the cell in the life sciences. They thought it was impossible to have access to representation, but isn’t this the current state of science? Newton had no access to the forces of attraction, neither did Darwin to the succession of species, nor Mendel to genes. S C I Mathematical, scientific and technical texts, and more generally texts of a certain level (philosophy, literature, etc.), are full of such variations in the meaning of words, although the authors try to make them unambiguous. Science is reduction, and the following ideas are a drastic reduction of the psychological phenomenon, but at least they offer possibilities to describe and analyze some important processes of representation. The meaning of the in the symmetry in sentences 3 and 4 is the meaning of the universal quantifier. The la in the fortress or in line d in sentences 1 and 2 has a deictic value: “this fortress”, “this line 101 d”. Obviously the correspondence between the signified and the signifiers is not a one-to-one correspondence at a lexical level. The succession of leaps in the operative and predicative forms of mathematical knowledge inevitably causes difficulties for students. Teachers are not sufficiently aware of these jumps. Four different components of representation can be distinguished, not as independent of each other, but as distinct in nature: (1) the stream of consciousness, (2) language and other sets of symbols, (3) concepts and categories, and ( 4) sets and subsets of schemes. Representation When we move from statement 3 to statement 4, a new transformation takes place: retention of lengths and angles becomes an object of thought, isometry. Now, the predicate is the inclusion relation between two sets: the set of symmetries S and the set of isometries I: Machine Translated by Google 212 Besides that, thought is frequently accompanied, or even directed, by linguistic and symbolic processes. Vygotsky has made this point very well. In the field of mathematics, numerical and algebraic notations constitute a very important part in the conceptualization and reasoning processes, although these are not concepts by themselves; musical notation is not music either, but symphonies would not be possible without it. What would mathematical thought be without language and symbols? Obviously, the predicative form of knowledge is essential, even if this is not the first form of knowledge. Every individual has some experience of stream of consciousness. This is the most obvious proof of the existence of representation as a psychological phenomenon, even if it does not provide us with a fair and sufficient conception. This almost permanent flow of images (visual, auditory, kinesthetic and somesthetic) accompanies both wakefulness and sleep, as well as a certain awareness of one’s own gestures and words, sometimes only outlined in the mind. Usually, we cannot analyze this flow of percepts, ideas, images, words and gestures, but it testifies that the representation works in a spontaneous and even irrepressible way. The stream of perception is an integral part of the stream of consciousness, also the stream of imagination, whether or not it is associated with perception. of concepts and categories in the selection of information. The importance given here to consciousness is not contradictory with the existence of the unconscious phenomenon, or with the fact that there are privileged moments of sudden consciousness, not reducible to the ordinary flow of consciousness. Concepts and categories The fact that perception is a component of representation is important for psychological theory because it is in the study of perception that one sees the essential role language and symbols Concepts and categories form the system with which we select information, with the purpose of directing our activity in the most relevant way. This meaning of representation is not as direct as the first two, because it rests on the thesis that perception is an important component of representation, even when we do not have words to be associated with the objects and relationships upon which the organization depends. of our activity. The word ”concept” is taken here in a broader sense than usual; It is normally restricted to the explicit objects of thought, whereas here it is extended to concepts-in-act that are very often implicit in the course of activity. This is why I use the expression “operational invariants” 102 (instead of “concept” and “theorem”) as much as I can. The distinction between conceptualization and symbolization is essential, to the point that the understanding of words and statements by different people, particularly between students and teachers, is not simply a binary significant/signified relationship, but a ternary one with the interpretation privileged by the Without words and symbols, representation and experience cannot be communicated. the stream of consciousness Machine Translated by Google It is essential for psychologists to recognize the central role of activity in the development of representation, competencies, and concepts. Because language and symbols play an important role in conceptualization processes, many 2 To calculate the height I must know the volume and the area, and divide the volume by the Conclusion 213 1 To calculate the volume I must know the area and the height, and multiply one by the other. 3 Volume is proportional to area when height is held constant, and to height when area is held constant. This reading requires much more than understanding multiplication and division operations and the meaning of letters. It is not always mentioned in textbooks; however, this is the real reason for the formula. area; this reading is more difficult than the first, since it is its inverse. Schema and subschema systems operative invariants. A compelling example of such processes is the understanding of a formula such as that for the volume of rectangular prisms: Whatever role symbols play in the conceptualization process, concepts and symbols should not be confused. Where V= volume of the prism, A= area of the base and H= height of the prism Therefore, the operational form of knowledge must be considered as a component of representation. Schemas are essential: they organize gestures and actions in the physical world, as well as interaction with others, conversation, and reasoning. Consciousness often accompanies the activity, but only partially: it is especially related to the goals and sub-goals, evaluating the relevance of the captured information, controlling the effects of the action. The structure of consciousness is different from the structure of activity: we are aware of the most relevant properties of objects, but we are more or less ignorant of how activity is generated and how subschemas are activated by superschemas. . This hierarchical organization gives opportunity for improvisation and contingency: schemas and sub-schemas are frequently evoked by contingent aspects of situations; this is the reciprocal character of their adaptive function. When students have to use it, they can read and interpret this formula in various ways. Here are some of their interpretations: V=A x H Representation is a dynamic activity, not an epiphenomenon that could accompany the activity without nourishing or guiding it. Representation is neither a dictionary nor just a library, but also a functional resource: it organizes and regulates action and perception; at the same time, it is also the product of action and perception. Machine Translated by Google Vergnaud, G. (1983). Multiplicative structures. In R. Lesh & M. Landau (Eds.), Acquisition of math concepts and processes (pp. 127–174). London: Academic Press. Piaget, J. (1968b). The formation of the symbol in the child: imitation, play and dream, image and representation. Lausanne: Delachaux and Niestlé. Vygotsky, L.S. (1962). Thought and language. Cambridge: MIT Press. There 103 are specific features in mathematical concepts that need to be considered as such. This is the main reason, both theoretical and practical, why it is more fruitful to use the framework of conceptual fields than logical structures to analyze the continuities and discontinuities of development in mathematics; also to imagine the appropriate situations to prompt and help students move through the multifaceted complexity of the field. References Revault d’Allonnes, G. (1915). Schematism. Minutes of the 43rd session of the French Association for the Advancement of Sciences (pp. 563-574). Paris: Masson et Cie. Finally, the operational form of knowledge and the predicative form are intertwined at all levels. There is no need to oppose one to the other; both are necessary to analyze the difficulties experienced by children and the way in which they can overcome them. Janet, P. (1928). Full text of the courses at the Collège de France, Chair of Experimental and Comparative Psychology. The evolution of memory and the notion of time. Paris: Chahine. 214 Revault d’Allonnes, G. (1920). The mechanism of thought: mental schemes. Philosophical Review, XC, 161–202. Piaget, J. (1968a). The birth of intelligence in children. Neuchâtel: Delachaux and Niestle. Researchers identify conceptualization and symbolization, as if the activity of enunciation and symbolization were sufficient roots of knowledge, particularly of mathematical knowledge. This is not the case. The analysis of the situations and the schemas shows that the conceptualization process already takes place in the simplest forms of the activity (even without language): the reason is that no action can be efficient without the identification of some objects and their properties. Even the most complex concepts, to gain meaning and operationality, need to be contextualized and exemplified in situations. Therefore, from the point of view of development, a concept is in short: a set of situations, a set of operative invariants (contained in the schemes), and a set of linguistic and symbolic representations. 104