To begin our unit on Surface Area and to review the concept of area, students were given a bag of irregular shaped objects, string and 1-centimeter square grid paper. With these materials students were asked to determine, as accurately as possible, the area of each of the irregular shaped objects. Students were challenged to figure out how they could use the materials they were given to determine an accurate area for each of the objects. This task asked students to develop an understanding and/or appreciation for the true meaning of area. They were not able to use a formula or calculator to calculate the area, but instead had to connect their understanding of what area actually means to the tools they were given and how they would determine an accurate area for each of the objects.
Students figured out that they could trace their objects onto grid paper and count the squares, or partial squares, to get an estimation of the area. Eventually students learned that they could find the perimeter of the shape, using the string, and create a rectangle (a shape that they are familiar with) on their grid paper to determine a more accurate area. Students then recorded their areas on the SMART Board so that we could compare methods to determine which was more accurate and see where we saw discrepancies. As you can see below, this was not a task that students could complete on their own, in order to be successful they needed to collaborate with one another. Students collaboration began with brainstorming strategies that they could use to try to determine area, to multiple hands working together to keep the string as close as possible to the shape to get an accurate perimeter so that they could then work together to create a rectangle on their grid paper to find an accurate area.
Until next time,