IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: Saladin on October 24, 2009, 03:02:02 pm

Title: Easiest way to find the square root of a number
Post by: Saladin on October 24, 2009, 03:02:02 pm

Please tell me, especially astar, how to find the square root of a number without a calculator, in the easiest way possible....


There was a way but i 4got how to do it....

i think it was a challange that u put up, like who can do the sqaure root of a number in their head....

Title: Re: Easiest way to find the square root of a number
Post by: astarmathsandphysics on October 24, 2009, 06:47:07 pm

I will explain when i get home.

Title: Re: Easiest way to find the square root of a number
Post by: Dreams <3 on October 24, 2009, 09:27:33 pm

I have a method, like when you get for example the square root of 75..
75 is 25*3.. So the root of 75 = the root of 25 * the root of 3
The root of 25 is 5 so the answer will be 5 square root of 3..
Sorry but i cant get the symbols for the roots im still new hope you understand it

Title: Re: Easiest way to find the square root of a number
Post by: master786 on October 24, 2009, 09:54:07 pm

tht answer u gave from ur example is surd form...
how wud u do the same for 1096 or some bigger number .

Title: Re: Easiest way to find the square root of a number
Post by: astarmathsandphysics on October 24, 2009, 09:58:40 pm

square root of 65
squuare root of 64 is 8 so do 8+1/(2*8 )=8.0625
8.0625^2= 64.00390625
now do 8.0625-0.00390625/(2*8.0625)
which is about 8.0625-0.0039/(16.1)=8,06226 roughly

Title: Re: Easiest way to find the square root of a number
Post by: Dreams <3 on October 24, 2009, 10:00:47 pm

you can see the 1096 from whats its originated.
i can know that 1096 is 274*4 so i can do it  :)

Title: Re: Easiest way to find the square root of a number
Post by: master786 on October 24, 2009, 10:03:34 pm

thts a standard method of find the surdform ...
its not the easiest way ..
there are better methods.. one lik astar has shown ...

in ur case 274 has to be broken up nd den tht broken up number has to be broken up till there is no more breakup of it ..
its a long nd complicated method... u need to know tables for it :)

Title: Re: Easiest way to find the square root of a number
Post by: Dreams <3 on October 24, 2009, 10:04:59 pm

i see it an easy one there is easier ofcourse but its good for some numbers

Title: Re: Easiest way to find the square root of a number
Post by: master786 on October 24, 2009, 10:06:32 pm

yea for numbers which are small . nd easy to workout ...numbers tht sometimesdnt evenneeed solving ...:)
eventhough...thanks for trying to help :D
By the way as u r new ... welcome to the forum :)

Title: Re: Easiest way to find the square root of a number
Post by: Dreams <3 on October 24, 2009, 10:19:35 pm

thanks

Title: Re: Easiest way to find the square root of a number
Post by: Saladin on October 25, 2009, 05:52:24 am

I dont get it, show me step by step, i dont get the smiley in the middle.

Title: Re: Easiest way to find the square root of a number
Post by: Ghost Of Highbury on October 25, 2009, 05:57:13 am

Quote from: The Dude 321 on October 25, 2009, 05:52:24 am

I dont get it, show me step by step, i dont get the smiley in the middle.

removed the smiley. try again

Title: Re: Easiest way to find the square root of a number
Post by: astarmathsandphysics on October 25, 2009, 07:21:42 am

The smilex should be an 8