Subtracting 10
🦸♂️ Subtracting 10 is actually one of the easiest math tricks ever! You don't even have to count.
Do this: Read the concept below, then try the quiz or activity.
Concept
Subtracting 10 is awesome because it has a secret pattern. You don't need to count back 10 times—that would take way too long!
🎯 The "Disappearing Ten" Trick: Teen numbers (like 12, 15, or 18) are all made of a bundle of 10 and some extra "ones". * 15 is one "10" and five "1s".
If you subtract 10 from 15, you are just taking the whole bundle of 10 away! What's left? Just the five "1s"! So, 15 - 10 = 5.
Example: 19 - 10 = ? Just take away the "1" at the front (which stands for 10). The answer is just the 9! 19 - 10 = 9.
Try it
Make the 10 disappear!
Instructions: Use the trick to solve these facts instantly.
Problem 1: 14 - 10 = ? * Take away the bundle of 10. What is left? * Answer: ___
Problem 2: 17 - 10 = ? * Answer: ___
Problem 3: 12 - 10 = ? * Answer: ___
Problem 4: 10 - 10 = ? * Answer: ___