#1 2021-01-07 17:01:23

ericnumberking

Member

From: Vancouver

Registered: 2018-02-06

Posts: 5

Multiplying Large Numbers in your head

This is a quick way to multiply two-digit numbers by 11 in your head. Created by a banker believe it or not.

Let's say you are trying to multiply 72 x 11.

Which equals to 792

- Split 72 in to two digits (72 becomes 7 and 2).
- Then add these two digits together (7+2=9)
- Now place 9 in the middle of 7 and 2 and what do you get? 792

Pretty sweet eh?

Let's try that with another number . . . 56 x 11
which equals to

- 56. So 5 And 6
- 5 + 6 is 11 (Just carry the one to the first 5. So 5 becomes 6)
- Answer  is (Drumroll . . .) = 616

Try it out!

Last edited by ericnumberking (2021-01-07 20:35:59)