This set of unit fraction puzzles (square tarsia puzzle) consists of 4 difficulty levels. It is based on unit fractions of denominator 1 to 12 in a cute monster theme. Level 1: 3 sets, each with different arrangement of fractions (Use for teaching and guiding child how to use this puzzle and also, matching unit fractions) Level 2, 3 and 4: 2 sets for each level, each with different arrangement of fractions These levels are arranged in increasing difficulty level. Suitable for children that jus