Using the Unit Division Board, the child practices the tables of division with the dividends 1-81 and divisors 1-9. The material consists of: a) a wooden board with 81 cavities in 9 rows of 9, with the numbers 1 to 9 printed both at the top and vertically along the left side; b) a wooden box with blue lid containing 81 green beads and 9 green skittles.