The child learns quantities through counting objects.

HOW DO WE LEARN MATH?

“This system, in which a child is constantly moving objects with his/her hands and actively exercising his/her senses, also takes into account a child’s special aptitude for mathematics.  When they leave the material, the children very easily reach the point where they wish to write out the operation.  They can then carry out an abstract mental operation and acquire a kind of natural and spontaneous inclination for mental calculations.” -Maria Montessori

Mathematical materials are designed to isolate a single mathematical idea or concept

Once the numbers 1-10 have been mastered, the child moves on to quantities of numbers, counting, addition, subtraction, skip counting, multiplication, and division.  Special concrete materials are used to teach all of these abstract mathematical concepts.