how can i find out square root of a number if square root sign is not on your calculater? any formula plz help

Answer 1

Raise it to the power 0.5

Answer 2

Finding square roots by guess & check method
One simple way to find a decimal approximation to, say √2 is to make an initial guess, square the guess, and depending how close you got, improve your guess. Since this method involves squaring the guess (multiplying the number times itself), it actually uses the definition of square root, and so can be very helpful in teaching the concept of square root.

Example: what is √20 ?
Children first learn to find the easy square roots that are whole numbers, but quickly the question arises as to what are the square roots of all these other numbers. You can start out by noting that (dealing here only with the positive roots) since √16 = 4 and √25 = 5, then √20 should be between 4 and 5 somewhere.

Then is the time to make a guess, for example 4.5. Square that, and see if the result is over or under 20, and improve your guess based on that. Repeat the process until you have the desired accuracy (amount of decimals). It's that simple and can be a nice experiment for children.



Example: Find √6 to 4 decimal places
Since 22 = 4 and 32 = 9, we know that √6 is between 2 and 3. Let's just make a guess of it being 2.5. Squaring that we get 2.52 = 6.25. That's too high, so make the guess a little less. Let's try 2.4 next. To find approximation to four decimal places we need to do this till we have five decimal places, and then round the result.

Guess Square of guess High/low
2.4 5.76 Too low
2.45 6.0025 Too high but real close
2.449 5.997601 Too low
2.4495 6.00005025 Too high, so between 2.449 and 2.4495
2.4493 5.99907049 Too low
2.4494 5.99956036 Too low, so between 2.4494 and 2.4495
2.44945 5.9998053025 Too low, so between 2.44945 and 2.4495.

This is enough since we now know it would be rounded to 2.4495 (and not to 2.4494).

Answer 3

Several of the other posters have correct methods, but ones that don't give good accuracy quickly. Here's a better way:

If all your calculator has is addition, subtraction, multiplication, and division, you have to find the square root by successive approximation. Here's an example:
To find the square root of 11, take a first guess,
say 3. Now do
(3^2 +11)/(2*3)=20/6=3.3333
Now do
(3.3333^2 +11)/(2*3.3333)=3.3166
Now do
(3.3166^2 +11)/(2*3.3166)=3.3166
Since this is the same as the last approximation, the square root of 11 is about 3.3166.

This method is guaranteed to work no matter what your first guess is, but it works faster if your first guess is close. Also, in place of the square, you can simply multiply your approximation by itself. Keep as many decimal places as you want in the end result. You will seldom have to do more than 4 or 5 times through this procedure.

Answer 4

there is no exact formula to find it out.
we consider a example
find the square root of 625
here u arrange the numbers in two digits from last that is 6,25.
then we do the division method
__25______________
2 | 6,25
| 4
| ___________
45 | 2 25
2 25
__________
0
below are steps


| step 1: here we take the
squares of
numbers that is
1x1=1
2x2=4
3x3=9,4x4=16 etc we take 4 here the number is 6
step 2:then if any number comes
on the numerator we must
multiply the number by 2
here 2 comes so that
2x2=4.
then to divide 225
we must think what number
we can put after 4 to
get 225.start with 1
41x1= 41
42x2=84
43x3=129
44x4=176
45x5=225
when we put 1 we put it in numerator
and on divisor also use same
number
number
therefore square root of 625 is 25

|
this is one of the easiest way to do.when many figures come we can adopt this method.when we use the calculator we can just get the answer not the steps.
u can just do similar problems and be clear with this method.

Answer 5

There is no formula for taking square roots, but any calculator can be of help. First, make your best guess and see if your guess is high or low.
Then keep adjusting your guesses up or down until you reach a number which, when squared , is the number whose square root you are trying to find.
Example: Find the square root of 856.

Try 30: 30x30=900--too high.
Try 25: 25x25=625 too low
Try 29: 29x29=841 a little low

Up to here you can do the calculations without
your calculator and it is good for your concentration to try it. But at this point, keep plugging in numbers until you zero in on the answer.
29.5x29.5=870.25---high
29.4x29.4=864.36--high
29.3x29.3=858.49--high
Now, to save time, I'm going to guess that 29.2 will be too low, so I'll go ahead and try 29.25.

29.25x29.25=855.5625--low
29.26x29.26=856.1476--slightly high.
29.258x29.258=856.030564--getting close.





Now that's pretty close to 856, but if you want to keep trying to get even closer, you can keep trying slightly higher or lower numbers until you get as close as you want.

29.2575x29.2575=856.001306. Now you have found the square root of 856 to within 13/10,000 and that is close.

Answer 6

You can find out square root of a number if square root sign is not on your calculater by using inverse sign and x^2.

If this also not there , then use your intution:
multiply two values as per your intution.for e.g.sqrt 4
then multiply 1.8*1.8,1.9*1.9,2*2.

Answer 7

Read "Finding square roots using an algorithm" at

http://www.homeschoolmath.net/teaching/square-root-algorithm.php

It descibes the method I learnt when I was 11. It looks a lot like long division. When you get to the decimal point of the original number, just continue to bring down the next TWO digits.

Answer 8

USE exponent. There are some scientific calculator which doesn't show or have roots but have exponent.

Say square root is exponent 1/2
Cube root is exponent of 1/3
and so on...

Answer 9

you have a computer right? use the calculator on there and switch the view to scientific. that should solve your problems. there will be a square root symbol on the calculator that windows provides.

Answer 10

there's no set formula. Round up or down to the nearest # you know the sq root of, then estimate from there.

Answer 11

if u find a button "xy" (y being superscript), this is the exponent function. square root is the same as exponent 0.5