The 'Adding a Group' Strategy

Adding a Group is a quick strategy to derive a fact from another fact you might know. For example, 3 X 9 is nothing but (2 X 9) + 9. If the child remembers 8 X 5 but not 8 X 6, then adding a group can help them quickly derive this in their head.

For this, adding a group is a useful skill to master so that they can call upon it when needed.

Below is one example of how adding a group is introduced to kids in Monster Math.