Decomposing Numbers to 10

Decomposing numbers — taking them apart and putting them back together — is the foundation of all mental arithmetic. A child who knows that 7 is 5 and 2 more, or that 8 is 2 away from 10, can add and subtract without counting on their fingers. The ten-frame is the most powerful tool for building this understanding because it makes the structure of numbers to 10 visible at a glance.