This set of facts includes all the turn-around facts for the make ten facts. Students should use their knowledge of addition and fact families to solve these facts. For example, when solving 11 - 8, the student should ask, “What plus 8 equals 11?”.
Thirty‐six facts have at least one factor that is either 0 or 1. These facts, though apparently easy, tend to get confused with “rules” that some children learned for addition. Above all else, avoid rules that sound arbitrary and without reason such as “Any number multiplied by zero is zero”.