Assign the Cut and Paste Puzzles pages in the Student Activity Book. Students will need scissors and a glue stick. The problems on these pages allow students the opportunity for independent practice using the strategies developed in the beginning of the lesson. Two copies of Shapes A, B, and C are provided. The problems help to illustrate that cutting a figure apart and gluing it into a different shape does not change its area. Shapes A and B have the same area (36 sq cm) so they can be cut to fit on top of one another.
- What are some things that you know about area?
(Possible responses: area is the amount of space a shape covers; area is measured in square units; I can multiply the length times the width of a rectangle to find its area; I can find the area of a triangle by dividing the area of a surrounding rectangle in half.)
- If a shape is cut into pieces and put back together into a different shape, does the amount of space the shape covers change? (no)
- Does the area of the shape change then? (No, the amount of space the shape covers is the same so the area is the same.)
Display the Centimeter Grid Paper Master.
- Who would like to draw another example of a shape that is 36 square centimeters?
For a greater challenge, assign the Super Challenge: Cut and Paste Puzzle Masters. The problems are similar to those on the Cut-and-Paste Puzzles pages and involve using strategies to find the area of shapes.
When copying the Masters, do not copy them back-to-back. Students will need to be able to cut the shapes on each page.
