Description: Montessori Mathematics Material - the relationship between odd numbers and even numbers the white beads are odd numbers, black beads are even numbers The quatity of beads are from 1 to 10, the number on the board show the beads on the column Good teaching aids for kids learn number 1-10, the relation between number and quantity and the base connection between odd numbers and even numbers Material: Basswood Chocking Hazard - Small Parts! Children under 3 years old should play with the toys under parents supervision! Size Chart: Bead Length: Approx. 1cm/0.39inch Board L x W x H: Approx. 22.5x5.5x1.5 cm/8.86x2.17x0.59inch Package Includes: 1 Set Montessori Mathematics Material Toys Note: Due to manual measurement, there may be 1-2mm error in size