Squares and Odd Numbers

Add up odd numbers from 1 onwards and you get square numbers!

Like this:

Odd
Number
Running
Total
 
1 1 = 1 × 1
3 4 = 2 × 2
5 9 = 3 ×3
7 16 = 4 × 4
9 25 = 5 × 5
11 36 = 6 × 6
etc...

Is this some kind of magic?

odd square numbers

Not really, just look at this picture:

It is good to know this, as it may help you solve things one day.