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if the question says find the square root of 20736, is there an easy way to find the answer?
to build on the previous post...
√20763 ~
√20000 =
√(2*100*100) =
√2 * √100 * √100 =
√2 * 10 * 10 =
√2 * 100 =
1.4 * 100 =
140
i think if you know the approx sqrt of 2 then you could get an answer close to the actual thing
20736=2x 10^4if the question says find the square root of 20736, is there an easy way to find the answer?
I *highly* doubt you get that, and even if you did, the answers would not be close together.if the question says find the square root of 20736, is there an easy way to find the answer?
I *highly* doubt you get that, and even if you did, the answers would not be close together.
For a number this size I would look to narrow it down within 100 first. You know 10,000 = 100^2 and 40,000 = 200^2 so it's somewhere in the 100s. I'm just doing this as a check for when I look at my answer.
Come up with some factors. You have 20,736. This divides by 4 into 5,184. This divides by 4 into 1,296. This divides by 4 into 324. This divides by 4 into 81. So you have 4*4*4*4*81 (which happens to be 9^2). So you have 16^2*9^2 and the square root is 16*9 = 144.
I like dividing by 4 because 4 is a square itself and very easy to work with.
Unless you have some ridiculous number you can almost definitely work your way down to a couple perfect squares and a low number square root. Memorize sqrt(2) = 1.41 and sqrt(3) = 1.73.
If you had 20,735 for example you would divide by 5 and get 4,147. I would round to 4,145 and divide by 5 again to get 829. Then I'd round to 830 and divide by 5 to get 166. That's nearly 13^2. So I'd have 5*5*5*13*13 which is 5*13*sqrt(5) which is 65*sqrt(5). You can guess that sqrt(5) is approximately 2.2 and 65*2.2 = 143. That's pretty freakin' close. Again, you might want to try working with the 4s as opposed to what I did up there with the 5s. When I used 5s I had to divide 3 times which left me with a sqrt(5). If I divided by 4 three times, I would still have all perfect squares.