Overview of the Lesson / Lesson Activities / Students' Ways of Thinking/ Assessment

1. Body Measurement Tools

If Lesson 1A is the introductory lesson, it will be important that students employ a less precise tool for the first measure, and a more precise tool for the second measure. Hence, we suggest providing a cm. (or inch) ruler that requires multiple iterations to measure the person's arm-span (e.g., a 15 cm. ruler), and also, that this type of ruler be used to measure another person's head circumference. For more precise measurement, use a meter stick for the arm-span and a tape measure for the circumference of the head. For the area of a person's hand, use the large grid paper included in the Appendix to measure the area of a cutout of a person's hand. The area of a hand is measured more precisely with smaller grids, because more complete squares are included in the count. These are also included in the Appendix.

2. Recording Measurements  

Each student's measurement is recorded, along with the condition of measurement. If students will work in groups, then each group receives several sets of colored index cards. Different colored index cards make it easier to keep track of each measurement condition. For example, red cards for measuring arm-span with a less precise tool, green cards for measuring arm-span with a more precise tool, etc. Students record each measurement on a separate index card. Cards are very handy because students can move them around easily as they attempt to design displays.

3. Re-measuring with a More Precise Tool

Students re-measure each body part with a better tool. It is up to the teacher to decide if this second measurement should follow immediately or be delayed. But it is very important for later lessons that each person measure again with a more precise tool.