Adding a Group is a quick strategy to derive a fact from another fact you might know. For example, 8 X 6 is nothing but (8 X 5) + 8. 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.
