Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 1 Measurement Concepts and Measuring Attributes with Instruments Students’ Understanding of Measurement A report on primary school students’ understanding of science and technology in Australia (Pattie, 1995) revealed that the effect of teaching was evident for the sample of 1161 children from 34 government and non-government schools. The study indicated that students performed at the higher levels when measuring temperature, length, and mass, reading a classification chart, and using space relationships—mathematical skills used in science and technology. However, such skills need to be further related to the scientific context. There was no overall difference in performance between males and females, or between children in urban, suburban and rural schools but there was a high correlation between socio-economic status and children’s understanding of science concepts and their performance of science skills. Measurement and Conservation Piaget originally thought that since pre-operational thinkers cannot conserve, then certain learning experiences for measurement should be delayed. It was previously considered that students could not explore the attribute, measure directly or indirectly until able to conserve but experience in classrooms clearly indicates that the experiences assist students to conserve. Children’s Development Piaget’s early research suggested that conservation of length, area, volume were issues in learning. He felt volume was much later than length and area. Later research suggested that informal play with capacity (filling containers with sand or water) showed that conservation of area is more difficult than expected and that volume (cm3 ) is more difficult than litre capacity. Mass is also quite difficult to sense without hefting in your hands and is visually confused with volume or capacity. A large, light object has a low density, and it has a low mass. However, a small, heavy object has a high density, and it has a large mass. Experiences with different types of objects is important. Later research suggests that the issues of conservation were clouded by perceptual dominance and experience and that measuring as a concept needs to link to everyday, situated learning e.g. ruler. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 2 Learning Tasks for the Reader Self-check on Conservation experiencing Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 3 Generic Development of Measurement Concepts No matter what attribute of measurement, certain critical aspects of measurement need to be developed. These are: Recognition of the attribute The different representations of the attribute, e.g. for length, we have length, height, width, distance, curved line, perimeter e.g. for area, we have flat, horizontal surface, curved surface, combined surfaces The idea of measuring comparing size directly comparing size indirectly needing to be more versatile, precise, non-visual The idea of a unit The idea of a composite unit made of joined units The idea of different base units Count Me In Measurement provides six levels of development. The project provides lessons for each level for each attribute: length, area, mass, capacity and volume. Level 1: Identification of the attribute includes directly comparing and ordering quantities Level 2: Informal measurement includes finding the number of units to cover, pack or fill a given quantity without overlapping or leaving gaps; knowing that the number of units used gives a measurement of quantity; using these measurements to compare quantities and realising that a quantity is unchanged if it is rearranged (the principle of conservation) Level 3: Unit structure includes replicating a single unit to cover, pack or fill a given quantity, either by drawing or visualising the unit structure; and realising that the larger the unit, the fewer units will be needed Level 4: Recognise, measure and record in conventional units Level 5: Use relationships between units and from the geometry to measure and calculate in smaller and larger units Level 6: Knowing and representing large units, consolidating and converting units, use scale Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 4 Learning Tasks for the Reader Measurement Activities 1 experiencing Find an interesting object in the room, measure different aspects of it and in different ways. What were critical aspects of your measurement? How many people can stand in the room? Compare the different ways people do this and also think about short-cuts, especially consider the natural units in the room. Make circular, triangular, square, other prisms with the lateral faces made by folding an A4 sheet of paper. Describe which prism and why has the largest volume from A4 paper. Show the length of string which is equal to the average height of your group of three Draw different shapes with an area of 12 square units. What did you consider? Make stacks of 24 cubes. Try making some stacks which are not rectangular prisms. Make them with different surface areas. Select a surface area and make stacks of different numbers of cubes. What did you have to know about to measure an object? Was it the only thing that you could have measured about the object? What does that tell you about attributes of objects and measurement? The area of the room could be measured using rectangular units. What does that tell you about units? What does it tell you about the development of the formula for the area of a rectangle? What did you learn about composite units if you tried short-cuts? What did you learn about the number of units needed when you measure with smaller units? Look at the three attached diagrams of squares on grids. Discuss how these require an understanding of a grid and the idea of composite units. Was the comparing of the volume of different prisms, a task about area or volume? Square centimetre paper could be used for greater accuracy. How accurate would the measurement of the base of the prisms be? connecting ideas Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Ch. 7, page 5 Measurement Concepts and Measuring Atributes with Instruments summarise and record The average height activity helps in developing the concept of addition of lengths and the meaning of average. Explain. Can a space measure a square unit but not be a square? What do these activities tell you about shapes, the distinction between shape and area, and the effect of perception on estimating area? Do all the shapes for 12 square units have to be polygons? Why and why not? How might the variance in shape for 12 square units be used in advertising or packaging? What do you learn about formulae for area and volume from the tasks? What previous approaches? Did you change your procedure/thinking during the problems? Why? What do these experiences tell you about the value of problem solving? What concepts did you use in finding the solution? How did you refine your understanding of these concepts? What do you think an area unit is? What might be meant by composite units of area? experiences helped you with your Length Boulton-Lewis, Wilss, & Mutch (1994) asked students to measure the length of two lines made from joined matchsticks; each configuration had a recognisable pattern. Younger students were likely to choose the familiar ruler rather than the unfamiliar measurement units (sticks) in order to attempt to compare the lengths of the two lines. Boulton-Lewis et al. suggested that the idea of introducing measurement with arbitrary, informal units may not be appropriate for students if they are to grasp the concept of measuring length because they do not have a mental model based on familiarity and past experience of the arbitrary units. By contrast, many syllabus documents have suggested that there be experiences with informal units before formal units. Willis (2005) suggests that there is much more about using units than what type. To begin with a unit is an abstract idea. The stick is only representative of that idea. Similarly, when talking about gaps and overlaps in tiling for area, the tile (even if it is 1 square centimetre) is a thing not the idea of an area unit that could take any shape. Early research also showed that young children could recognise that they would need fewer of a larger unit than a smaller unit to measure a fixed line. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 6 Area There have been several studies on various issues related to this concept. Doig, Cheeseman, and Lindsey (1995) investigated the effects of different material—paper squares, Dienes’ blocks and wooden tiles—on children's success in measuring the area of a rectangle. They found that children were least successful when they used the paper squares and most successful when they used the wooden tiles. Children who used Dienes’ blocks were most likely to confuse measurement of area with that of perimeter or length. However, the use of paper squares revealed inadequate understandings of area because students were more likely to overlap or leave gaps between the paper squares. Consequently, practice in tiling with rigid materials may not help students’ understandings of area (Outhred, 1993). If mathematical concepts are to emerge, it seems important that concrete experiences of covering areas should engage students’ visual imagery and analysis (Owens, 1994b) and should also involve student-student and student-teacher interaction about the ideas needing development (Hart & Sinkinson, 1988; Owens, 1994a). Clements and Ellerton (1995) interviewed a large sample of students on several test items used in basic skills tests in Australia. They showed that there were notable proportions of mismatches between correct/incorrect answers and nonunderstanding/understanding as probed during interviews. One of the items was to find the area of a trapezium consisting of a square and a triangle (half the size of the square) with only some lengths given. The study showed a large number of students did not understand the concept of area, how lengths relate to area, why different shapes have different formulae for calculating, or the value of visual/spatial knowledge. In another study Clements (1995) illustrated a lack of conceptual understanding for a student able to calculate the area of a triangle. Young children often hear the word area referring to place, and may think of area as somewhere to go—for example, the assembly area or the reading area—without considering it as a region. They do not seem to realise that such regions are twodimensional (2D) spaces enclosed by boundaries and that they can be covered with units (e.g., sheets of newspaper). Students may have covered small regions such as desks, books, and chairs with informal units and perhaps compared the two by counting the number of units needed to cover them. Such activities, intended to be introductory to the concept of area measurement, may in fact confuse students. The use of irregular shapes and informal units (e.g., potato prints) may result in the activity being dominated by counting, while ideas crucial to the concept of area measurement (e.g., overlaps, gaps, and congruent units) are ignored (Outhred, 1993; Willis, 2005). Willis emphasised that students who had counted to decide on the measure of an object’s length or mass were then unable to use this information to answer a question about whether the object was heavier than another or longer than another. A greater appreciation of the concept of covering would seem to be necessary if older students are to calculate areas meaningfully (see Mitchelmore, 1983, and Clements, 1995, for examples of typical student difficulties with area calculations). In observations of pre-school children covering squares, rectangles, and triangles with smaller cut-out rectangles, squares, and triangles, Mansfield and Scott (1990) have shown that students vary in their ability to choose appropriate unit shapes, in their persistence, and in their turning and flipping tactics. The most difficult shape for the children to cover was an equilateral triangle with a point facing down. Familiarity with the shape to be covered seemed to increase success on the task. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 7 In a study by Wheatley and Cobb (1990), students were asked to cover a large square by selecting shapes from a collection comprising a square, several triangles, and a parallelogram. Some students chose only the parallelogram and tried to cover the square with it, an approach which suggested to Wheatley and Cobb that the students were matching lengths. Alternatively, students may have chosen the shape that appeared to be largest. Other errors included leaving gaps, especially on the sides, and overlapping pieces or the sides of the square. Drawing may be one way of linking experiences with concrete materials to students’ mental models of tessellations. Several researchers (e.g., Mitchelmore, 1983; Outhred, 1993; Outhred & Mitchelmore, 1992) have suggested that drawing is an important tool in developing students’ knowledge of rectangular arrays and in making links to multiplication. Outhred (1993) found that many students had difficulties visualising or drawing tilings of square units to cover rectangles when the squares were only shown on adjacent sides of the rectangle or indicated by side marks, particularly for rectangles with large dimensions. Some students’ drawings suggested that they did not understand what features of arrays were important in constructing tessellations of squares. Owens (1992, 1993) found that students in Years 2 and 4 had difficulties imagining tilings of squares, rectangles, and triangles to cover larger shapes. For example, in the activities illustrated in Figures 1a and 1b, they had difficulty in predicting the number of smaller triangles that would be needed to cover the larger ones. Very few students commented on the amount of space covered when asked what was the same about different arrangements of five squares (pentominoes); nearly all focused on the number of tiles (Owens, 1993). (a) Tangram triangles (b) Pattern-block triangles Figure1. Shapes made during spatial activities (Owens, 1993). The studies mentioned above, especially those by Outhred (1993) and Owens (1993), emphasise the importance of spatial thinking and visualising when students cover and compare shapes. To learn about tiling, students need to identify suitable units, to transform shapes to other orientations, to recognise and partition shapes, and to identify key features of shapes (e.g., matching parts such as right angles or equal lengths). Owens (1993, Owens & Outhred, 1998) examined the drawings of students in Years 2 and 4 who were asked if specific units (squares, rectangles, right-angled triangles, and equilateral triangles) could be used to tile figures and how many units would be needed. Three factors that seemed to influence children's responses were summarised by Owens and Outhred (1998): 1. Size of tiles. While children seemed to know that there was a pattern for filling the space, some seemed to retain the shape but not the size of the tiling unit. Children who drew tessellated tiles without regard for size usually felt that the space was being adequately filled. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 8 2. Recognition of tile features. Students frequently used the sides and corners to begin filling in spaces with tiles. The type of corner seemed important to some students in deciding if a particular tile would be likely to fit. Students had difficulty recognising a trapezium as a composite of tessellated right-angled triangles, despite prior experience with concrete materials. 3. Judgments about drawings. Some students decided that overlaps or size or gaps did not matter if the result was "close" enough, that is, they based their judgments on their spatial sense and ignored slight discrepancies in their drawings. Children who thought the tiles should fit often filled gaps with additional tiles, disregarding shape or overlap. Others were influenced by inaccuracies in their drawings and said that the shapes could not be made by fitting tiles together. While Owens was carrying out her study, Outhred (1993) was independently exploring children's difficulties in representing arrays and how such difficulties are related to performance on area measurement tasks. Her research suggests that knowledge of array structure provides a link between measurement and multiplication concepts in the context of rectangular area measurement. She found that knowledge of array structure was essential for children to relate the lengths of adjacent sides of a rectangle to the number of squares that would cover it. These results indicate why activities with concrete materials may not be sufficient to help children understand the formula for the area of a rectangle. When measuring the area of a rectangle using concrete materials children do not require awareness of row and column structure because the structure is determined by the materials, rather than by the child's thinking. The effects of specific types of instruction on children's use of lines to represent rows and columns was investigated with children in Years 1 and 2 (Outhred, 1993). The findings suggested that teaching children that squares in an array were all the same size was not the most effective method to help children to perceive array structure. Teaching children that the squares are aligned or that there are the same number of squares in each row (column) seemed to be more effective methods for moving children from drawing squares individually to representing rows (columns) of squares using lines. McPhail (1997) has continued to explore how young students develop knowledge about tessellations and area. With a series of four lessons she has shown that young students in Years 1 and 2 can learn about area. Her lessons allowed students to first make their own area enclosed by a length of braid. The children also painted or rubbed large triangles and squares which were later used to make large visual displays of tessellations. In addition, the students had many small squares and triangles. They were asked to make large squares and triangles as well as covering given ones. The cardboard tiles had the edges in black so that arrays were easily seen. This seemed to facilitate children drawing tilings using arrays rather than individual tiles. Interestingly, the children applied many number facts in telling the teacher how many tiles they had used. Some used the ideas of repeated addition of rows of tiles, others counted a number and then added on the subitised remaining number of tiles. Students could explain the patterns of the triangular covering. Willis (2005) provides another challenge in saying that a tile is a measuring instrument. Rigid tiles for area may not cover a thinner object without discussing cutting up the tile. Unlike the fluid units used in capacity that flow around and fill the container, this does not automatically happen with area. They concluded that understandings should include: (a) the instrument we choose to represent our unit should relate well to the attribute to be measured and be easy to repeat to match the thing to be measured; Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 9 (b) to measure consistently we need to use our instrument in a way that ensures a good match of the unit with the object to be measured; (c) units are quantities and so we can use different representations of the same unit so long as we do not change the quantity (Willis, 2005). Volume Toh (1993) compared the effectiveness of computer simulated experiments with that of parallel instruction involving hands-on laboratory experiments for teaching volume-by-displacement concepts. The purpose of the simulation was to have students test their misconceptions rather than simply being told about erroneous misconceptions. The study consisted of 389 students from 6 Malaysian schools. The results indicated that the computer-assisted group was significantly better in terms of learning gains in the cognitive categories of knowledge and application. The computer simulated different conditions such as same shape, different masses; or same mass, different shapes. While it is not easy to do this with concrete materials, nevertheless the experience assists in moving students on from limited conception about the volume by displacement. In summary, teachers should be aware of the confusion between area and perimeter because students do not develop the concept of area, they do not develop area formulae, or they are just told to use the formula (with the meaningless idea of lengths becoming area rather than the formula involving numbers only without the unit attachment and that it is a formula associated with a specific shape, e.g. rectangle); can establish the area concept through painting an area, tiling, discussing no gaps, and the nature of shapes; should not use just solid tiles that structure exercise and prevent abstraction, or lead to counting exercise rather than an area experience; should know the value of tiles that are not square; should know the value of recognising patterns and drawing grids (and discuss drawing difficulties); should recognise the importance of visualising and estimating; should build on children’s intuitive dissecting of areas to assist in calculating. Units Students need to develop concepts like area that are measured. Spatial experiences and knowledge about shapes will help when comparing informally or directly or when selecting a unit for measuring. Later knowledge of the properties of shapes will assist students to calculate areas. We also use standard units so that there is no confusion. Students need to be familiar with these, to know about how big they are, and to be able to estimate in these units. In particular, students need experiences in (a) selecting objects that represent the unit, (c) estimating, and (d) measuring in order to develop a sense of these units. Composite Units An important concept in measurement is that of a composite or iterable unit. For example, when the young students put tiles in rows and count by rows, for example, 3, 6, 9, they are using the row as a composite unit made up of 3 units. This idea is also a Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 10 basic concept in both multiplication and our place value system with a ten being a composite unit of 10 ones. While students first develop a sense of units which are within their grasp, they expand these into larger and smaller units using the notion of composite unit. Students eventually need to be able to change from one unit into another. A good understanding of the composite unit will assist this procedure. Metric Units and the Place Value System Measurement can assist students to develop their understanding of the place value system. For example, students can read off the length of an object from a ruler in (a) metres, (b) metres and centimetres, and (c) centimetres. The ruler can establish the idea that a metre is a composite of 100 centimetres but also that a hundred is a composite of 100 ones. More importantly, the idea of one being a composite of 100 hundredths is also established. So, for example, a string might be 1.23 m or it can be written as 123 centimetres or 1 m 23 centimetres. Activities allowing for these various descriptions will assist students to make the links. They will take time. Recognising Structure Students need to recognise structure in order to develop their measurement concepts. Mulligan expresses this in the following diagram. See your earlier activities on area of a room, making a ruler and area sheets for units. Learning Tasks for the Reader Self-check on Measurement Sense experiencing 1. At what temperature does a person suffer from hypothermia? a. 25o b. 30o Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 11 c. 35o d. 40o e. 45o 2. The height of a child in Year 2 is about a. 1 cm b. 50 cm c. 100 cm d. 150 cm e. 1 000 cm 3. A small fish tank would hold about a. 1 L b. 20 L c. 100 L d. 1 mL 4. The area of floor in front of the desks is about a. 1 000 m2 b. 100 m2 c. 10 m2 d. 0.5 km2 5. A house block has a house with gardens covering the same area as the house. The area of the block is about a. 0.5 hectares b. 1 hectare c. 1.5 hectares d. 2 acres 6. An A4 sheet is about a. 10 cm2 b. 100 cm2 c. 1 000 cm2 d. 10 000 cm2 7. The space taken up by an engine of a small car is about a. 1.4 L b. 1.4 m3 c. 1.4 m d. 1.4 kg 8. A litre of water has the same mass as: a. a commonly available bag of rice b. a house brick c. a can of condensed soup d. a dozen eggs e. 2 apples Think about this problem. If you hold a man’s handkerchief diagonally, how many are needed for the length of a horse? Before wheelie bins, how high was the garbage bin? Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments connecting ideas Ch. 7, page 12 What role does a sense of size play in measurement? How did (a) visualising; (b) experience with the unit; and (c) prior experience impact your decision-making? What influences the necessary degree of accuracy? What are some ways that you can encourage students to develop a good sense of volume and area? Why should students have many activities to encourage them to construct both a sense of area and formulae for the area of a rectangle and a triangle, and the volume of a prism. Why are square units so useful? Look in the Syllabus at the experiences that students need for developing their own area formula for a rectangle, a rectangular prism and a triangle Include in your summary for area comments on: summarise and record (a) the importance of number of rows and number of square units per row (b) how to deal with sides that are not whole numbers (e.g. folding rectangular areas) Include in your summary for volume comments on: (c) Number of layers and number of cubic units in each layer (d) The link between 1 cm3 and 1 mL. Outcomes for NSW Mathematics K-6 Syllabus Table 1 gives the NSW outcome statements for measurement. Table 1 Outcome Statements for Measurement Early Stage 1 Stage 1 Stage 2 Length Area MES1.1 Describes length and distance using everyday language and compares lengths using direct comparison MES1.2 Describes MS1.1 Estimates, measures, compares and records lengths and distances using informal units, metres and centimetres MS1.2 Estimates, MS2.1 Estimates, measures, compares and records lengths, distances and perimeters in metres, centimeters and millimeters MS2.2 Estimates, Stage 3 MS3.1 Selects and uses the appropriate unit and device to measure lengths, distances and perimeters MS3.2 Selects and uses Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Volume and Capacity Mass Time Passage of time, its measurem ent and representat ions area using everyday language and compares areas using direct comparison MES1.3 Compares the capacities of containers and the volumes of objects or substances using direct comparison MES1.4 Compares the masses of two objects and describes mass using everyday language MES1.5 Sequences events and uses everyday language to describe the duration of activities measures, compares and records areas using informal units Ch. 7, page 13 MS1.4 Estimates, measures, compares and records the masses of two or more objects using informal units measures, compares and records the areas of surfaces in square centimeters and square metres MS2.3 Estimates, measures, compares and records volumes and capacities using litres, milliltres and cubic centimeters MS2.4 Estimates, measures, compares and recordsmasses using kilograms and grams the appropriate unit to calculate area, including the area of squares, rectangles and triangles MS3.3 Selects and uses the appropriate unit to estimate and measure volume and capacity, including the volume of rectangular prisms MS3.5 Selects and uses the appropriate unit and measuring device to find the mass of objects MS1.5 Compares the duration of events using informal methods and reads clocks on the half-hour MS2.5 Reads and records time in oneminute intervals and makes comparisons between time units MS3.5 Uses twentyfour hour time and am and pm notation in real-life situations and constructs timelines MS1.3 Estimates, measures, compares and records volumes and capacities using informal units Measuring Instruments Students need to understand measuring instruments. For example, the scale on a jug looks like a ruler for measuring length but it is indicating volume. How can we get students to understand that? Most rulers have gradations that are equally spaced, i.e. 1 and 2 are spaced at the same distance as 2 and 3. This is not always the case depending on the purpose of the instrument. Students also have to understand how to read the gradations that are not marked and they need to know that the number is not the point but the measure from the start. For example, it is the amount of water in a cup; at zero the cup is empty. What Instruments can we Make for Measuring If students are going to appreciate how a ruler works and that the numbers on the ruler are representing the length from the start of the ruler, then they need to make a ruler. It can be done by lining up some base 10 long blocks and marking off and numbering a strip of paper, cloth or plastic. Alternatively they can make lengths of 1 cm, 2 cm etc, put each length on their long strip of paper with the starts together and marking the length and writing down the length on their long strip. 0 5 Figure 1. Lengths of paper being used to make a ruler. A volume measure can be made by using a jar and lids. As the student puts in another lidful, they mark where the water comes to and the number of lids now in the Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 14 jar. This helps students to see the linear marks on the measuring jar as representing volume. Students can bring to school all sorts of measuring instruments that can be found in the home and garage. All sorts of gauges are used. These can be discussed even if the students do not fully understand what is being measured. They can see the needle moving through the numbers on bathroom scales; they can look at the different widths of the sparkplug gauges; they can watch an amp metre needle swing. Students can make various time clocks. Learning Tasks for Readers Making Measuring Instruments experiencing Make a pair of calipers to pinch the fat on your back to measure fat. Make a tapered diameter measure to see how big a ring you make when you touch your thumb and forefinger. Make a tiny trundle wheel to measure around your leg or waist in cm (the wheel can have a circumference of 10 cm.) Make a balance - spring balance or an equal arm balance. What is a measuring instrument? Outline some important early and later experiences that students should have for establishing the concept of mass, connecting ideas What important concepts in measurement should students learn? What are important concerns in teaching about measurement? summarise and record Using Measuring Across the Curriculum Clearly measuring is an important skill in Science and Technology. Students should investigate in science and use measuring as a tool. For example, take different brands of nappies and investigate which is the best. For older students, two great tasks are from MCTP Activity Banks (Lovitt & Clarke, 1989) called Danger Distance and Map of Australia. Both encourage visualisation with measurement. Finding old measuring instruments around the farm, old mine site or dump, designing and making measuring instruments can also be fun. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 15 Measuring and reading measurements and interpreting data are all important ideas in investigating nature and studying, for example, animals. Human Society and Its Environment provides plenty of opportunities for using measuring and interpreting information. Map work and built environments are just two areas. For Personal Development, Health, and Physical Education, there are many ideas. What does it mean to have a pulse rate of 60 beats per minute? What does it mean to have diversity in height at a particular age group? What does it mean to have 10g of fat per 100g, compared to 1g of fat per 100g? Learning Tasks for the Reader Mathematics and the Human Body What is our lung capacity? experiencing What is meant by lung capacity? How can we find out the volume of air in our lungs? There are machines which can be discussed. One approximate way is to blow up a balloon with one breath. Discuss how you can get the volume of the balloon. One way is by putting the balloon in a full bucket of water and measuring the displacement of water. Remember that fit people and non-smokers improve their lung capacity. Lung capacity grows from childhood to adolescence. How much skin do we have? Estimate how many sq cm for the sole of your foot. What is the skin mathematically and what is meant by the size of our skin? A discussion on this questions should be about covering of the surface and surface area. Areas can be in different forms including surface areas and this can be modeled by wrapping with newspaper. Discuss how to find the area of different parts of the body. Arms can be represented by curved cylinders which can be flatten out to rectangles (or near rectangles). Discuss ways of measuring the rectangles with informal square units. If you add up the size of all the parts of the body surface in sq cm and try to convert to sq m, ask yourself whether the answer seems sensible. How do you convert sq cm to sq m? A rule-of-thumb for estimating the total amount of skin is to multiply the size of the sole of the foot by 100. This is then a quick way of deciding on the percentage of skin burnt on a burn victim. Try out this rule-of-thumb and decide what percentage Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments connecting ideas Ch. 7, page 16 of skin an arm would be. Compare the sizes and ratios for a small child and for an adult. Discuss the following suggestions for activities. Think about: the equipment that might be needed, the different approaches that might be taken, questions that students may ask and how to answer their questions, and how to get them to investigate. How much carbohydrate food is in a packet of crisps? How much in a potato? Which is better food? (Health note: We need quite a bit of carbohydrates with fibre but not much fat each day.) Students undertaking this investigation may: - investigate the nutrition information - ask about why grams are used, learn that g is the symbol for grams - weigh potatoes, decide what an average one might be - compare the amount of oil in a packet of crisps by weighing that in cooking spoons Do we drink enough water? (Health note: Children should drink about 8 cups per day.) Compare drinking bottles, glasses, and other drink containers. Discuss how we can compare - cups, L, mL (depending on age). (Teachers need to think about how they can measure bubbler drinks.) Compare the different shapes of containers with the same amount of water. Students can extend the activity and measure more accurately. Discuss how the perceptions of size are used in marketing and how different shapes help storage and handling. And here we can link in the eyes and the brain interpreting what we see and the effects of stored information. How big is your heart? The heart is said to be as big as the person’s fist. Think about and try out how to get its volume (by displacement of water). How flexible is our heart and how does it respond to help us? Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments summarise and record Ch. 7, page 17 Find your pulse and count how often it beats. Do this when you enter the class after running around at recess. It is usually a little stronger and it will be easier to find, especially at the neck. Then discuss how to count it. Discuss the idea of rate. It is not an easy idea but really important for some discussion in primary school as it is a major idea in later studies. One way of doing this is to show that in quarter of a minute is quarter the number in a full minute. The ratio is the same. Take the pulse rate after sitting for awhile and then after some vigourous activity – the same for the whole class. Compare different pulse rates and discuss how adaptable the heart is to meet their needs. If some studnets are regular swimmers, exercise regularly, or run around more than others, you might be able to compare their slower rates after exercise (or how much quicker their rate returns to normal). Discuss the effect of fitness on heart rate. Why do students learn more about mathematics through: investigations and real-life contexts? How do you make sure that you are covering mathematics and other Key Learning Area outcomes when giving students investigations like those listed above? Can these activities be modified for different age groups? If so, give some examples. Planning Events, Times and Calendars The ancient Babylonians were keen astronomers, astrologers, and travellers. They made links between the number of days in a year and the time it took for a cycle of seasons to pass and the earth to rotate around the sun. We have 365 days as closer to the time taken to complete the cycle but the number 360 is more useful because it can be divided up into many different ways. Calendars vary from place to place and culture to culture. Yearly and daily periods of time are described differently in different cultures. A diagram that shows how one Indigenous Australian tribe describes the time of the year shows the close links between times and knowing when to fire the grass so that bushfires do not start and when to get certain food. The overlap of events is easiest represented by segmented concentric circles. One circle represents the wind seasons, another the plant seasons and so on. Any period can be determined by the coincidence of these events (Harris, 1989). Planning Events and Feasts. Many Pacific Islanders organise large feasts. There is much mathematics involved in deciding on the quantity of food to prepared in the Marae kitchen, how many bundles (about one for every 50 people) are needed and how to go about gathering the food together. For people who are growing the food, months of preparation is involved in planning gardens so that the food is ready for the feast. Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens Measurement Concepts and Measuring Atributes with Instruments Ch. 7, page 18 Learning Tasks for the Reader Planning Events, Times and Calendars experiencing connecting ideas Do you know why we have 360o in a circle? What numbers go exactly into 360? What events or gatherings do you plan? What mathematics do you use when you plan for these events? Look closely at the lessons on time in the Syllabus. Compare this with the set of outcomes in Table 1. Which has greater emphasis in Kindergarten: (a) recognising the attribute of time by comparing the time taken for events, or (b) reading the clock. What are some difficulties that young students will have reading analogue clocks? summarise and record Summarise the new ideas that you have learnt about measurement, especially time, as a result of considering the differences in cultures. Summarise the ideas of attribute composite units culturally determined measures metric system links with decimal place value Creating Space: Professional Knowledge and Spatial Activities for Teaching Mathematics Kay Owens