This is a perfect supplement to your perimeter unit. It meets CCSS 3.MD.D.8 There are 52 game cards. I suggest either printing them on card stock or glueing the paper on card stock then laminating for longer use.
There are 4 different shapes with the same perimeters. All sides are labeled in this game. Your students need to add up the perimeters and then ask other students for cards that have the same perimeter. I suggest students having scratch paper so they can add them up. There is an answer sheet. Each card is numbered and the numbers that share the same perimeter are listed on the answer sheet.
The preview is a jpeg picture of 8 cards.
Please contact me if you have any questions firstname.lastname@example.org. I hope your class enjoys this game as much as mine does!