Ages 5-7. Kumon Math Games workbook was developed to allow children to practice addition and subtraction skills through fun and challenging math puzzles. The enjoyable math puzzles will provide your child practice with simple calculation problems while developing his or her problem-solving skills. This workbook includes number review activities, coded addition and subtraction problems, calculation maze puzzles, number crossword puzzles, and many more puzzles, all presented in a progressional order that will allow your child to build calculation skills with ease.