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Wikipedia:Reference desk/Archives/Mathematics/2014 August 24

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August 24

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Hi i am Er. Mohit Iyer and i am a good mathematician. I am curious about maths and i love to solve the problems.

Today, i want to gave some idea about How to solve SQUARE OF A NUMBER?

if you want to solve the square of 25? (25)*(25) then firstly, you have to find 5*5=25 then you have to find 2*2=4 now, you have 425 now, you have To find 2*5*(power)=2*5*2=20 now,add this multiplication by 425 20* 625 that is the required answer. — Preceding unsigned comment added by Er. Mohit Iyer (talkcontribs) 07:46, 5 September 2014 (UTC)[reply]

It works. For a two digit number, you have a tens digit (A) and a ones digit (B), so the number is 10*A+B. Squaring it gives (10*A+B)2 = 100*A^2 + B^2 + 20*A*B. Your first step was to put A^2 in front of B^2, which is the same as 100*A^2 + B^2. The second step was A*B*2 and adding that to the tens digit, which is the same as adding A*B*2*10.
The method runs into complications if you want to scale it up to cubes or three digits, however, so it does not generalize well. Good thinking, though. SamuelRiv (talk) 18:38, 12 September 2014 (UTC)[reply]