Inverse Relationship Between Addition and Subtraction: When Students Ask
- Why should I learn the facts?
If you know one fact in a fact family, you can find the other facts. So if you forget one fact, you have a tool to find others. - How are facts related?
They use the same three numbers. - Do all families have 4 facts?
No, doubles have only two facts in their families; one addition fact and one subtraction fact. - What is a fact family?
Addition and subtraction facts that belong together because they have all the same numbers make up a fact family.