Question

How to multiply a square of a number starting with 5 without actual multiplication.

Answer 1

If I'm reading this right you can use addition:
\[5x^2=x+x+x+x+x+x+x+x+x+x\]

Answer 2

Take 50

= 50+50+50+50...50 times

Answer 3

oh i know maybe what you mean

Answer 4

like
\[45^2\]

Answer 5

method is this: you will end in 25
one more than 4 is 5
5 times 4 is 2
answer is 2025

Answer 6

or
\[65^2\] one more than 6 is 7
6 times 7 is 42
answer
4225

Answer 7

was that the question?

Answer 8

@Satellite73......
if the no is 52 square....then.....what is the answer.....without actual multiplication....

Answer 9

i dunno. i know the trick for b5^2 where b is a between 1 and 9. not for 52^2 but that can't be bad because you know (50+2)(50+2)=2500+200+4=2704

Answer 10

of course all of these require some 'actual multiplication'

Answer 11

52+52+52+..

Answer 12

want a hoot, watch some of these
http://www.youtube.com/watch?v=IIwlBjNLpjI&feature=related

Answer 13

http://www.youtube.com/watch?v=I9t-gYnPNaw&feature=relmfu

Answer 14

http://www.glad2teach.co.uk/fast_maths_calculation_tricks.htm

Answer 15

i love these. love them

Answer 16

I am a genius!.... my brain is now faster than a calculator...

Answer 17

Oh! I have to pay.....

Answer 18

really? not on youtube

Answer 19

isn't it? i love it!

Answer 20

No for the Math fast tricks CD..

Answer 21

oh, i should get it, but maybe not

Answer 22

impressed with how long it took to get
\[x=\frac{1\pm\sqrt{5}}{2}\] maybe

Answer 23

Moderators all woke up, I see:-)