THE ROLE OF THE COMPUTER IN THE TEACHİNG AND LEARNİNG LİNEAR ALGEBRA Asst.Prof. Sinan Aydın Yüzüncü Yıl University, Faculty of Education Department of Primary School Education, Van/Turkey. Sinanaydin1704@yahoo.com ABSRACT The availability of computers has forced mathematicians to rethink the way they are teaching mathematics. When an operation can be performed quickly and satisfactorily by a computer, an instructor has to ask `What is it that a student really needs to learn in a course and How?’. One of the essences of teaching is to help students learn the material that they need. In this study we discuss The Role of the Computer in the Teaching and Learning Linear Algebra. Also it deals with some strategies which were used and the computer projects that were developed for linear algebra courses. 27 students in 2-A class (experiment group) and 28 students in 2-B class (control group) in Mathematics education of Primary Department in the Education Faculty of Yüzüncü Yıl University, which is in the 2nd Term of 2006-2007 Academic Years, were assigned as the sample of the study. The resulting improvement in the students learning has been remarkable. Keywords: Linear Algebra, Computer Projects, Teaching Strategies. INTRODUCTION The innovations in the technology create the necessity to re-examine our approach to teaching the subject in linear algebra. One of the basic essences of teaching is to help students learn the subjects that they need. The availability of computers has forced mathematicians to rethink the way they are teaching mathematics. If a mathematical operation can be done quickly and satisfactorily by a computer, an instructor has to ask `What is it that students really need to learn in a course and How?’. A simple reality that every teacher of this course can see easily is that linear algebra is a very useful in the modern scientific world. Also another reality for this course is that many applications of linear algebra don’t happen without a computer. We know that some mathematical software programs such as Matlab, Mathematica, Drive and Maple can do many computations in the basic linear algebra course. In this point, it is very important to make an effective integration of computing into the linear algebra classroom. Some researchers studying on linear algebra are working on how to incorporate computing effectively, how we will teach and how the students will learn (Carlson, Johnson, Lay, Porter, 1993; 42 ; Dorier, 2002; 877 ; Uhlig, 2003; 148 ). One widespread idea is that mathematic students tend to be less computer user than some other majors as physics, engineering and architecture. When a mathematic instructor integrates computing into the courses, Students will have more confidence and more useful computer experience. So an answer to the question above mentioned is that students need to understand well the main mathematical concepts ant to be able to apply them in different situations via computer. Many linear algebra instructors agree with the idea that students of this course need to take first the basic concepts and the theorems, than to master in the basic hand calculations and finally, after these steps, to use a computer to do arithmetic (Sierpinska, Trgalova, Hilel, Dreyfus, 1999; 125). If it is done so, students can concentrate much on the conceptual ideas instead of trying to get the arithmetic right in the solution. Also when a linear algebra instructor uses a computer, he can do some calculations that are not otherwise possible in class. For instance, he can ask questions, in talking about an advance calculation, to the class how to their approach the problem. He is able to do exactly by computer what his students tell him to do. By help of this procedure, students will be willingly, and are motivated to participate in next steps of the course. Using computer in linear algebra makes it possible to ask theoretical questions which are arithmetically too complicated to do with pencil and paper in class. There is a similar situation in this question that which vectors are in a subspace? And how we understand two subspaces are the same subspace. For example, in vector space theory, every subspace of a vector space has infinitely many bases. It is possible for many linear algebra students to know that every subspace has a special and predetermined basis. When the students find basis of the row space of a matrix by computer, they can meet some different basis for the subspace. This computation brings out the idea that there can be more than one basis for a subspace. Some linear algebra researchers say that some pure mathematicians can worry that using computers in a mathematic course will turn students into unthinking way (Axler, 1995; 141; Harel, 2000, 182; Rogalski, 1996; 215). This approach could be true in some conditions but it is easy to avoid in linear algebra; in my opinion, computer can be used to motivate learning the concepts and the theory of linear algebra. Also in this course, the theory plays a basic role in computations. For instance, in solution of linear equations systems, we know the famous theorem that every solution of a linear equations system can be written as the sum of a particular solution of the system. This theorem can be seen as to be difficult by students to understand without computer. Matlab gives us an approach to understand the formal theory and a procedure to find the general solution of the linear equations system. 1036 This article deals with the two special strategies that were used and some computer projects that were developed for linear algebra. TWO STRATEGİES IN USİNG COMPUTER a. Using software programs to explore new linear algebra concepts A computer classroom with individual stations needs to be available. One of the main mathematical software programs, as matlab, can be used as a resource. Instead of giving examples that satisfy a definition or checking that they satisfy a certain list of properties about a concept, instructor lead students through a series of exercises to work with examples and explore their properties. This approach is the central point of using computer in linear algebra. For instance, noncommutativity of the product of matrices becomes more real and clearer for students if they produce examples by themselves in computer. Of course, a computer is not necessary to do this arithmetic but using computer makes it possible to do it in class without spending much time. b. Using computer projects to motivate students The abstractness of the linear algebra concepts allows students to model a wide variety of concrete problems. To show this abstractness, Instructors give individual projects to them. Also every student should have a chance to choose an applied problem in his/her area of interest. Since many of the current linear algebra textbooks emphasize applications to different fields, there are many source of problems(Bretscher, 1997; Cullen, 1996; Larson & Edwards, 1996; Lay, 1997; Moore & Yaqub, 1992). Students will make an exploratory work, look for required patterns and make conjectures during these applications. ON A SPECİAL PROJECT What follow is part of the project on linear transformations. The parts consist of a problem that has been divided into several sections. Students discover pieces of linear algebra information than use it to arrive at conclusion. Also they use computer and a software program in necessary steps. METHOD The study took place during the 2nd Term of 2006-2007 Academic Years in Mathematics education of Primary Department in the Education Faculty of Yüzüncü Yıl University. 27 students in 2-A class (experiment group) and 28 students in 2-B class (control group) were assigned as the sample of the study. While no computers were available in the classroom of the control group, and the topics followed the traditional order found in most linear algebra textbooks, the experiment group was received computer assisted teaching. The classes of the experiment group were hold in a computer laboratory room. Exploratory work with linear algebra computer programs and a few projects constituted during the semester. Only the final exam was used for the evaluation of the study and there were no additional writing requirements. The data obtained was analyzed with the help of descriptive statistics. FINDINGS The following table compares the grades obtained by the students in the pre-test exam of the groups. Table 1: Summary of the pre-test results with respect to the groups. Group N St.Dev. df t Sig. Experiment 27 14,51 1,37 Control 28 12,67 1,10 1. 2. 3. 4. 5. Apply L to the vectors in the standard basis of R5. Write the resulting vectors as columns and use them in the given order to from a matrix M ( we call M the matrix associated to L with respect to the standard bases in the domain and in the range of L). Check that to find the image of any vector v, we obtain the same result if we use the definition of L or if we multiply the matrix M by the column v = ( x1, x2, x3, x4, x5 )t. Find the nullspace (or kernel) of L. Find the dimension of the image of L. Check that dim (R5) = dim (kerL) + dim (Im L). 1,04 0,3 According to the tablo1, there was no difference in the level of the groups when they started the education program at the probability value of 0,5. So we can say that the experiment group and the control group were the same level in linear algebra course at the beginning of the term. The following table compares the grades obtained by the students in the post-test (the final) exam of the groups. Table 2: Summary of the post-test (the final) exam results with respect to the groups. Group N St.Dev. df t Sig. Experiment 27 69,92 13,03 Control 28 58,75 16,02 Let L: R5 → R4 be defined by L( x1, x2, x3, x4, x5 ) = (x1- x5, 2x1- x2, x1+ x3, x4 ). 53 53 2,57 0,01 As shown at the table2, the difference, between the experiment group and the control group, is significant (p<0,05). According to this finding, the improvement in learning of the experiment group is due to the using of the teaching strategies described in this article. RESULTS Linear algebra provides a vital arena where students can see the interaction of mathematics, and machine computation. The integration of computation and theoretical mathematics is so natural in linear algebra that students can use their experience with linear algebra as a starting point for seeking similar integration in other mathematical areas. So linear algebra deserves a central place in the curriculum of mathematic program. Students need to learn how to integrate a theoretical and computational understanding of mathematics. Computer-based instruction may lower the quality of learning linear algebra if too much emphasis is placed on individual work with computer. An improvement in learning can be due to 1037 the combination of the teaching strategies. Incorporating computer into teaching linear algebra works best when it is done with strategies that promote critical thinking and increase communication between students and teachers. When the algorithms of linear algebra are properly understood, students spend less time on computations and more time discussing problems, theorems and proofs. REFERENCES Axler, S. (1995). Down with determinants. Amer. Math. Monthly, 102, 139-154. Bretscher, O., (1997). Linear Algebra with Applications. Upper Saddle River, Prentice Hall. Carlson, D. & Johnson, C. R. & Lay, D.C. & Porter, A.D. (1993). The linear algebra curriculum study group recommendations for the first course in linear algebra. College Mathematics Journal, 24, 41-46. Cullen, C.G., (1996). Linear Algebra with Applications. Upper Saddle River, Prentice Hall. Dorier, J.L., (2002). Teaching Linear Algebra at University. Proceedings of the International Congress of Mathemtictians. Harel, G., (2000). Principles of Learning and Teaching Mathematics, With Particular Reference to the Learning and Teaching of Linear Algebra: Old and New Observations. On the Teaching of Linear Algebra, Kluwer Academic Publishers, 177-189. 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