Fun With Sums- Addition & Subtraction "Children put together these simple and easy to assemble match - ups to solve simple Addition and Subtraction problems. Set includes 30 self - correcting three- piece puzzles with problem/sum on the first two pieces and the answer on the third piece in concrete and visual way. With the help of picture clues which children can count to find and check their answers. A simple and fun way to practice maths facts.