A number is a mathematical concept that defines a quantity. It can be represented in several forms:

- a series of numbers each having a position value,
- a combination of words,
- a decomposition in base-ten (number of hundreds, tens, units),
- a set of graphic symbols : a cube represents the number of units, a bar of 10 cubes represents the number of tens, a plate of 10 bars or 100 cubes represents the number of hundreds.

This animation is a random generator of numbers between 0 and 999. Each question consists in associating two equivalent representations of the same number.

For progression in learning, four ranges of numbers are proposed. The model of representation of the number can be fixed at the level of both the question and the answer.