Memorizing multiplication tables can feel overwhelming for elementary students. But the 9 times table has a built-in mathematical pattern that makes it the easiest table of all. In fact, you have the entire 9 times table right in front of you: on your ten fingers.
How to Do the Finger Trick
Hold both of your hands out in front of you, palms facing your face. Number your fingers mentally from 1 to 10, starting with your left pinky (1) and ending with your right pinky (10).
To calculate 9 × N, fold down finger number N. The fingers to the left of the folded finger represent the tens digit. The fingers to the right represent the ones digit.
Let's Try 9 × 4
- Count to your 4th finger from the left (your left index finger).
- Fold that 4th finger down.
- Look at your hands:
- To the left of the folded finger: 3 fingers are up.
- To the right of the folded finger: 6 fingers are up.
- Put the digits together: 36. Therefore,
9 × 4 = 36!
Let's Try 9 × 8
- Fold down your 8th finger (your right middle finger).
- Count the fingers to the left: 7 fingers.
- Count the fingers to the right: 2 fingers.
- The answer is 72!
The Secret Pattern of the Number 9
Why does this work? Notice something special about every multiple of 9 from 1 to 10:
| Problem | Answer | Sum of Digits |
|---|---|---|
| 9 × 1 | 09 | 0 + 9 = 9 |
| 9 × 2 | 18 | 1 + 8 = 9 |
| 9 × 3 | 27 | 2 + 7 = 9 |
| 9 × 4 | 36 | 3 + 6 = 9 |
| 9 × 5 | 45 | 4 + 5 = 9 |
The digits of every multiple always add up to 9! And the tens digit is always one less than the number you are multiplying. When students see this pattern, math stops feeling like arbitrary memorization and starts making logical sense.