With this trick, in just 5 minutes you will learn how to quickly multiply 20×20 in your head. You could easily multiply 2 numbers from 11 – 19, with no calculator.

(A) Example: 14 x 17

Steps:

- Remember the larger number of the two (17)
- Add 17 from the second digit 4 (taken from 14): 17 + 4 = 21
- Get the sum (21) and add a zero on the last (or multiply it by 10): 21 x 10 = 210
- Multiply the second/last digit of the 2 numbers 4 (from 14) x 7 (from 17) = 28
- Add 210 + 28 = 238