Finding a square root by subtraction

Think about the number 16

Step 1: Start with 16 and subtract the first odd number

1. 16 - 1 = 15
   Step 2: From the answer subtract the next odd number
2. 15 - 3 = 12
   Step 3: From this answer subtract the next odd number
3. 12 - 5 = 7
   Continue like this until you read zero.
4. 7 - 7 = 0

It took 4 steps, hence the square root of 16 is 4.

Try this yourself with other square numbers.