Posted on Nov 21, 2010

# Square Large Numbers in Your Head Quickly

Quick: What's 192...without your calculator? (361.) Squaring complex,...

76K views lifehacker.com## Interest

Discovered by itskyle321

on Mar 31, 2010

on Mar 31, 2010

# Stumblers Who Commented On This Page

## lorgix

### lorgix

"Squaring complex, two-digit numbers..."

There are complex two-digit numbers now!?

Anyway, it's the reverse conjugate;

a^2=(a-b)*(a+b)+b^2

example:

18^2=16*20+4=324

Posted on Nov 15, 2010

## yossarian22t

## Tim

or factorise 106^2=(100+6)^2=(10k+36)+100x6+10636