KIDS AND TEACHERS LOVE BOOM CARDS! NO PREP, NO PAPER, NO PROBLEM. Area and perimeter with a missing side with help students with so many areas in the fourth grade curriculum. It reviews the formula for are and perimeter. It will help them with division and multiplication. I use it as a tool on the smart board to show the students how to do it. I use the FAST Play for practice and then they sign in for an assessment.