Estimating the Square Root of a number

Estimating the Square Root of a Number Video

 

The square root of a perfect square is an integer. You can estimate the square root of a number that is not a perfect square.

Example:

Estimate to the nearest whole number.
First list some perfect squares and look for the whole numbers near by 69.
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, …
Observe that 69 lies between the perfect squares 64 and 81. That is, 64 < 69 < 81.
Now find the square root of each number.
So, is between 8 and 9.
Since 69 is much closer to 64 than to 81, the best whole number estimate is 8. 

http://hotmath.com/hotmath_help/topics/simplifying-square-roots.html