Everyone loves a challenge. Use these Numbers 1-20 Fun-to-Know Puzzles to help children build confidence and achieve success. Fun, two-piece puzzles teach children numbers 1 to 20. Only matching pieces fit together. Matching helps children identify numerals, understand number values and practice counting. Photos offer real-life learning. Durable, 3'' x 3'' pieces come in a sturdy storage box. Each number is represented on the 20 two-piece puzzles. Puzzles are ideal for teaching ages 3 and up.