CountFast 20 and Multiples of 10

This module introduces a learning tool or trick to help solve any number multiplied by 20, or any number that is a multiple of 10, very fast. So again, the concept of taking what may look like a difficult problem and utilizing a tool or trick to make it simpler to solve.

After this module, the student will be able to use mental calculation to solve any number times 20, or any number that is a multiple of 10, very fast.