Do you want to multiply fast without memorizing your multiplication table? If yes, then this post is definitely for you.
When I was in Grade school, I was taught a multiplication technique using fingers. The technique is used for multiplying number from 6-10. If you know this technique, and you did not memorize your multiplication table, you should be able to multiply fast.
Steps in Multiplying Fast Using Your Fingers
1. Assign numbers 6-10 to your fingers (both left and right hand) as shown in the first figure.
2. Connect the fingers assigned to the numbers that you want to multiply (8 x 7).
3. Count the connected fingers including the fingers below them and multiply by 10 (5 x 10 = 50).
4. Multiply the number of fingers on the left hand and the right hand above the connected fingers (2 x 3 = 6).
5. Add the result in steps 3 and 4 (50 + 6 = 56). Therefore, 8 x 7 = 56.
Now try the technique in multiplying the following numbers: 6 and 5, 9 and 10, and 7 and 7. See if the result is correct.
The technique above is very similar to the Polish hand magic. If you are interested about the mathematics behind this strategy, read Why Finger Multiplication Works.