Multiply 20×20 – Easy Trick

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

(A) Final Answer: 14 x 17 = 238

(B) Example: 18 x 13

Steps:

  • 18+ 3 (from 13) = 21
  • Add a 0 to 21 = 210
  • 8 (from 18) x3 (from 13) = 24
  • 210 + 24 = 234

(B) Answer: 18 x 13 = 234

A Simple Magic Math Trick for KIDS:

This is for kids that want to do a simple magic math trick to their friends, parents, guardians, cousins, etc… Ask them to think of a number from 1 to 100. You are going to guess what number they are thinking by letting them take this 3 easy steps:

  • Step 1: Tell them to multiply their number by 2
  • Step 2: Then tell them to multiply it by 5
  • Step 3: Then let them say what is the total number they come up

Then, to guess their number. Just drop the 0 (the last digit is always 0) from the answer they gave you 🙂

Sample: Mom is thinking of the number 15

  1. 15 x 2 = 30
  2. 30 x 5 = 150
  3. Drop the 0 from 150 = 15

Learning math is fun. So kids, don’t be lazy to go to school and have fun learning. “Knowledge is Power”

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