9 times table finger hack

About the video

In the video a child folds one finger down and reads a 9 times answer from their hands. At home 2 players take turns: the caller reads 10 problems and the player uses the finger hack to answer within 5 seconds. 9 x 4 is the same as 4 groups of 10 minus 4, so the tens digit is one less than the number and the ones digit is 10 minus the number. That is why the fingers to the left show the tens, the fingers to the right show the ones, and the two digits always add up to 9.

What your child learns

• Use the finger hack for 9 x 1 to 9 x 10
• Explain why the two digits add up to 9
• Link 9 x a number to 10 x the number minus it

What's on the worksheet

1. 1Predict first
2. 2Record your hands
3. 3What did you see?
4. 4The math behind it
5. 5Fill in the 9s
6. 6Match the answer
7. 7True or false
8. 8Word problems
9. 9Explain it