The Relative Numbers presentations give the child a concrete understanding and practice performing operations using relative numbers. Understanding the concept of relative numbers is a pre-requisite for work with exponents, squares, cubes, and algebra. It is an integral component of the math curriculum, which Montessori herself compared to the "tree that supports the parts" for the child's understanding of the concept of numeration. The pre-requisites for this unit are the Function of the Decima