Math Tricks!

Multiply Up to 20X20 In Your Head

In just FIVE minutes you should learn to quickly multiply up to 20X20 in your head. With this trick, you will be able to multiply any two numbers from 11 to 19 in your head quickly, without the use of a calculator.

Try this:

• Take 15 x 13 as an example.
• First add 15+3 = 18
• Add a zero behind it (multiply by 10) to get 180.
• Multiply the covered lower 3 x the single digit above it the "5" (3 x 5 = 15)
• Add 180 + 15 = 195

That is it! Wasn't it easy? Practice it on paper first! 

Jessica To