# What do you have to do to a number to find out its square route?

Like, say a number like 25, what would you have to do to that number to find it's square route?

Please explain this!

### 6 Answers

- efqyLv 71 decade agoBest Answer
find a number that when you square it gives the number you're trying to take the square root of.

e.g. you need sqrt(289).

You might guess 15. 15^2 = 225. That's too small. So you need a bigger number.

[Here's a trick to improve your guess: Take the difference between them (289-225) and divide by twice your guess at the square root and round down.

64/30 = 2.1333 round down to 2. New guess is 17.]

It helps if you try to remember the first few squares (up to 100)

(I've learned up to 36^2, they come in very handy in a lot of multiplication calculations.)

- 4 years ago
what is the square root of a number? Think in exponential numbers; 7 * 7 = 49, therefore the square root of 49 is 7. A negative times itself will be a positive, therefore, -7 * -7 = 49, so the square root of 49 is also -7. To get a negative product, you must multiply a negative by a positive, which are two completely different numbers. Therefore, there cannot be a radical negative. Got it?

- 1 decade ago
Finding the square root of a number is the inverse operation of squaring that number. Remember, the square of a number is that number times itself.

square of n = n^2

sqaure of 25= 5x5=5^2=25

- 1 decade ago
There is no method to find the square root its put into a calculator and memorize common square numbers.

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- ted sLv 71 decade ago
if you do not mind doing some numerical work then x² = a means compute a sequence of numbers { x0,x1,x2,x3,....} where x0 is chosen arbitrarily and x(n+1) = { (xn)² + a } / {2xn} , n = 0,1,2,..

ex √ 102 is the answer to x² = 102....chose x0 = 10 since 10² = 100

x1 = [ 100 + 102] / [20] = 10.1 , x2 = [ (10.1)² +102] / 20.2 = 10.09950495, which is √102 accurate to 8 decimals