Describe how to estimate a non-perfect square root to the hundredths place without using a calculator.

1) find the perfect square closest to the number
2) take that square root, and then divide your number by that number
3) take the average of the perfect square root (the whole number) and the result of dividing your original number by that root. 

Example: Approximate square root of 27
Closest perfect square: 25
Square root: 5
27 ÷ 5 = 5.4
Average between 5 and 5.4 = 5.20
5.2² = 27.04. Fast and not a bad approximation!