Quality Montessori Materials for Toddler,
Primary and Elementary Environments.
E&O Montessori USA.
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.