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How to multiply 55 to itself faster

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Here's a simple way on how to multiply 55 to itself faster?

 

We know that 55 multiply to itself can be represented by the figure :

 

55

x 55

====

3025

 

The answer is 3025.

 

NOW, any numbers being multiplied to itself like

 

55 times 55 ,

 

75 times 75 ,

 

35 times 35 or

 

25 times 25 ,

 

can have a faster answer being done from the mind. HOW??

 

For example? Taking 25 x 25 (25 times 25) can be taken AS

 

25

x 35

=====

625

 

NOTICED that 2 multiply to 3 is 6 then simply append 25. You will get 625. The trick is to ADD 10 to the number then proceed with FIRST NUMBER multiplication.

 

 

 

 

ANOTHER EXAMPLE for 55 multply to itself as in 55 x 55.

 

 

55

x 65

====

3025

 

NOTICED that 5 x 6 = 30 , so we append 25 to the number, the answer becomes 3025, which is the correct answer. Get it? Append 25 to 30 becomes 3025! So 55 times 55 equals 3025.

 

 

 

 

Enjoy! smile.png

Edited by Fearless Staff
  • Like 1

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Nice tutorial. Simple, handy and easy to understand. +1 :)

Edited by Panini*Hobbit@mp3

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That's clever! I've never come across that method before :) I like it =]

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I was thought this in grade 3

 

I wish I was.. These kinda things were what made me love maths when I was in primary school (age 4-10/11).. Then in secondary school (age 11/12 - 16), we weren't taught any intriguing things like this.. Probably why I ended up hating maths, never going, and getting a B in my final exams lol (sounds ok but it was the lower end of my results)

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i use booths algorithm

 

55 in binary is 00011011

other num is x00011011 -----> right shift this number 8 times and add to the number above

:l33t

for some reason i am addicted to binary language !

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I knew this since 2nd Grade. :P

But then again I knew the formula n/2(a1+an) too. Dang I was one smart kid. Still am. :P

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wow very cool.

 

My schools didn't teach anything like this either, just the good ol' multiplication tables and brute force practice, good times.

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thank you guys for the likes and rating :P

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I knew this since 2nd Grade. :P

But then again I knew the formula n/2(a1+an) too. Dang I was one smart kid. Still am. :P

 

i knew that before i was born ! :rolleyes:

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Bet that those who learned this in school arent in the US...

 

Good Tutorial Thanks!

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