Here’s a fun way to teach and reinforce addition and subtraction skills! These 20 self-checking, 5-piece puzzles are designed to help children develop automaticity in addition and subtraction. Each puzzle is unique: the four corner pieces show an addition or subtraction problem, with the answer on the center piece! This set includes 10 two-side puzzles, plastic-coated and easy for small hands to manipulate, plus an activity guide.