Write-On/Wipe-Off Addition/Subtraction Fact Family Triangle Mats by Didax

Double-sided mats feature a fact family triangle on one side and a triangle diagram on the other, so students and teachers can fill in the 3 digits to practice addition/subtraction skills. For use with dry erase markers, the 9x12" mats are made of durable, flexible plastic. 10 mats per package. Grades 1-3.