Mathemagic #1 | How to find the square root of a number within 3 seconds (without using calculator)??

in #math7 years ago
<![Screenshot_20170723-183330.png]()html>

What's up steemians...Welcome to the magical episode of Imagicnation ! A blog where we will reveal the answers to some of the most interesting & curious questions related to science...


Hey guys...Today, I'll be teaching you a secret trick which most physicist/mathematician often use but never share with their students ! It is actually a trick about how to find the square root of a square number within 3 seconds (without using calculator). So, are you excited?? Then here we go...


Suppose, take a number, say 3969.

Now, before starting the trick, we all must know about its basics, i.e, if a number ends with its unit digit 1, then the unit digit of its square will also be 1. 

Similarly:

For 2 it's 4, for 3 it's 9 and so on...

And, if you understood this we can now start solving some problems step by step. 


Step 1:

The first thing we need to do now is separate the given number (3969) into two parts, i.e, the RIGHT TWO DIGITS and the REMAINING DIGITS.

By that I mean to say: separate 3969 into 39 (REMAINING DIGITS) & 69 (RIGHT TWO DIGITS).

Now, our answer also comes in two parts _ _, (say A and B). 

(where A is the left digit of the ANSWER and B is the right digit of the answer)

The RIGHT TWO DIGITS gives the value of B while the REMAINING DIGITS gives the value of A.


Step 2:

So, to find the value of B we take the unit digit of RIGHT TWO DIGITS (69). So, here it is 9.

Now, from what we learnt from basics, we find out which are the numbers from 1 to 9 which when squared gives 9 at the unit place. So, they are 3 and 7.


Step 3:

To find the value of A we take the REMAINING DIGITS (39) and find out the biggest number whose square is smaller than 39

So, here that is 6 (since the square of 7 is greater than 39, we reject it)


Step 4:

Now, we now that the value of A is 6 and so we write 6 in the left side.

For the value of B we have to either select 3 or 7. So which should we select ??  See the final step for that.


Step 5:

Finallly, to find the value of B we do the following things:

i) Multiply A (i.e 6) with its next digit

-i.e, here 6 x 7 = 42

ii) Compare 42 with the REMAINING TWO DIGITS (i.e 39)

iii) Here, REMAINING TWO DIGITS (i.e 39) is smaller than 42. So, we select the smaller number, i.e from either 3 or 7.  Since, 3  is smaller is than 7,

Hence, the ANSWER WILL BE 63 !!

[Here, if the REMAINING TWO DIGITS was greater than 42, then we should select the greater number, i.e, 7.]



So, BRAVO ! 

I hope you have understood the trick. But since it is new to you, you'll need a little bit of practice to answer in seconds.


...& if you have really understood it then find the square roots of the following numbers and comment me as fast as you can.

5184
2809
1936
5476
6084



...if you want more such stuffs, mention it below

and yes...dont forget to UPVOTE, FOLLOW or RESTEEM !



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Nice math trick. upvoted.
But I don't think it works for any number, only perfect squares.
3859 and 4079 give the same answer as 3969

it works for only perfect square numbers as mentioned in the article above...and thank you @point !

I love math tricks, and you gave a couple of good ones here! Thanks!

Thank you sir..lots of interesting posts to come soon....keep supporting...!

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thank you so much for the support @steemiteducation...just hoping that it reaches to maximum people so that it can save their time during calculations...

This is awesome

thank you sir @anneke...keep supporting....lot more to come...

Pretty cool trick. Does it work with bigger numbers, more than 4 digits?

thanks ...and definitely...it works for every perfect squares...give a try...

These steps are excellrnt and should assi

thank you @tanyaschutte...keep supporting...

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