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Contributor: Stefani Allegretti. Lesson ID: 14105
Are you ready to become a math magician? Get ready to learn about the make-a-nine trick to solve addition problems up to twenty!
Watch this!
Now get ready because YOU can be a math magician, too!
A super awesome make-a-nine trick will help you solve math problems up to twenty times faster than you can say 'abracadabra!'
Grab your magic wand (or your thinking cap), and get started!
Abracadabra, math magic awaits!
The first part of the make-a-nine trick is to find the hidden nine.
Try it with 8 + 11.
8 + ? = 9
You only need 1 more!
Now, break down 11 into two parts: 1 and 10.
Because you need to add 1 to 8 to make 9!
1 + 8 = 9
Great job! You made a nine!
Now, add what is left from 11, which is 10. (Remember, you took 1 away from the 11 to make 9.)
So, 9 + 10 =19
You did it!
So, 8 + 11 was changed to 9 + 10, which equals 19!
Excellent work, math magician!
Check out this trick in action one more time!
5 + 12 = ?
First, make a nine.
5 + ? = 9
You need 4 more!
Now, break the bigger number 12 into two parts: 4 and 8.
Then, add the 4 to 5 to make 9!
5 + 4 = 9
You made another 9!
Now, add what is left from 12, which is 8. (Remember, you took 4 away to make your 9.)
9 + 8 = 17
Wow, you did it again!
You turned 5 + 12 into 9 + 8, which equals 17.
You’re becoming a math magician!
You could even take 1 away from 8 and make the 9 into a 10 for easier addition!
Get ready for some more fun practice in the Got It? section!
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