Subtract Doubles
👯♂️ Doubles to the rescue! If you know your addition doubles by heart, then you automatically know your subtraction doubles for free!
Do this: Read the concept below, then try the quiz or activity.
Concept
A "double" is an addition fact where both numbers are exactly the same, like 5 + 5 = 10, or 8 + 8 = 16.
🎯 The "Un-Double" Strategy: Because addition and subtraction are opposites, you can use doubles to solve subtraction! Example: 14 - 7 = ? Does the number 14 make you think of a double? Yes! You know that 7 + 7 = 14. If 7 + 7 equals 14, then if you take one of those 7s away, you must have the other 7 left! So, 14 - 7 = 7.
If the number you are subtracting is exactly *half* of the starting number, the answer is just the same number again!
Try it
Let's un-double some numbers!
Instructions: Think of the addition double to find the subtraction answer!
Problem 1: 12 - 6 = ? * What double makes 12? ( ___ + ___ = 12 ) * Answer: 12 - 6 = ___
Problem 2: 16 - 8 = ? * What double makes 16? * Answer: 16 - 8 = ___
Problem 3: 18 - 9 = ? * Answer: ___
Problem 4: 10 - 5 = ? * Answer: ___