Everyone loves a challenge. Use these Opposites Fun-to-Know Puzzles to help children build confidence and achieve success. Fun, two-piece puzzles teach children positional concepts in pictures and words, such as full vs. empty. Only matching pieces fit together. Photos offer real-life learning. Durable, 3" x 3" pieces come in a sturdy storage box. The 24 two-piece puzzles are ideal for teaching ages 3 and up.