A square wooden board with 4 pegs that holds 4 balls of the same size. Placing the balls on the pegs is a challenging task for the infant. As the pegs seem to 'disappear' in the balls, the child experiences that the centre hole in the ball disappears too, and the shape becomes whole.
The Small Square Root Board is used by the children to build squares and to extract square roots. The wooden board contains 225 indentations for working square roots. Included with the board is a box of 100 each green, blue and red beads.