Search your Topic HERE....

June 02, 2012

Shortcut for finding Cubes

31 comments

sponsored links

Attention Friends... we've came to know that this method is not working for some numbers... So presently we are working on more efficient method than this... We advise you to avoid this method....

In our last posts we've discussed the method of finding Squares (read that post Here). In this post we shall discuss the method of finding cubes. This is very easy and simple method. You just have to put little concentration while learning and should do little practice so that you can do the process in a easy way mentally. And another thing you should keep in mind is, we are posting the step by stem inorder to make you understand the process in detail, but you SHOULD do most of these steps MENTALLY and only should put some important final results on paper. Now lets have a look at the method. In earlier method of finding squares we'd discussed finding the squares with the formula (a+b)2 , here we shall use the formula (a+b)3
Lets start with an example. Assume that you should find out the cube of 18. The general process is multiplying 18 to itself for 2 times (18 x 18 x 18). This process is time consuming and often people end up with the wrong answer caused by confusion and hurry. 
Ok, now lets use our method. here you should use the formula  (a+b) = a3 +b3+ 3a2b +3ab2. But here you should be little tricky. Have a look.........
Note : Here a or b should contain 3 digits. Or else, just put zeroes to fill the gaps so that you can avoid confusion while doing additions. So, the calculation will look like this.....
Here, please note that you are placing 0s to avoid confusion and to fill the GAPS. If you have some 2 digit number (say 25)  instead of that 1 in the above example, you should write that as 025.

Some Points to Remember : 
  • You should write a3  and b3 Side by side (no need to add them)
  • You should start writing the 3a2b term exactly below from the  a3  term.  
  • The 3ab2 term should end one number before the  b3 term.
Lets see another example,


Thats all for now friends. This method may look little confusing initially. Please do practice well so that you can understand the advantage of this method. Happy reading :)

sponsored links

31 comments:

  1. Hi i am unable to understand this process ...

    ReplyDelete
    Replies
    1. Which point you are unable to understand? Or do you feel the entire process confusing?

      Delete
    2. some solutions for 23 cube and 29 cube .. the answer is not geting as per process

      Delete
    3. Well, therez some problem with this method Sita, thats the reason we've updated a caution message. We'll try to upload a new method soon..

      Good Day

      Delete
  2. What about in case if we have no as 226 and 8828 and we have to find cube? How we have to calculate it through this technique.

    ReplyDelete
    Replies
    1. If you want to use this technique for 3 digits and 4 digits just divide those digits into 2 parts. The first part will b "a" and the second part will be "b". In your example you can treat 22 as a and 6 as b. Same logic with the second example too

      Delete
  3. l want steps for 55 cube.. i done it but i got wrong answer... please do the sum for me..

    ReplyDelete
    Replies

    1. 125 125
      3 75
      37 5
      ----------
      166 375

      Delete
    2. 1 2 5 1 2 5
      3 7 5
      3 7 5
      ------------------------------------
      1 6 6 3 7 5

      Delete
  4. Replies
    1. 8 729
      4 86
      10 8
      ---------
      24 389

      Delete
    2. But, the sum of 8729 + 486 + 108 = 9323 only
      not 24389

      Delete
    3. but the sum of 8729 + 486 + 108 = 9323...
      not 24389

      Delete
    4. write like this.....

      8729
      1 08
      486
      -------------------------
      24389
      ------------------

      Delete
    5. 8 7 2 9
      1 0 8
      4 8 6
      ---------------------------
      2 4 3 8 9

      Delete
  5. mam really its nice bt for some number its not working plz give other short way for them

    ReplyDelete
  6. It is very confusing,, I can share easy method to find cube..............

    ReplyDelete
  7. thank u some much sir it is best site

    ReplyDelete
  8. Hi friends the method is like this,

    The last digit of the 3a2b term shud b below the 3rd term from right, and the last digit of the 3ab2 term shud b below the 2nd term from right... After that add the and you will get the correct answer...

    ReplyDelete
  9. thanku sir ,i searched in many sites but finally i got it from urs

    ReplyDelete
  10. confusion hai is shortcuts trick me. can't find the cube of 58,46,49 etc..

    ReplyDelete
  11. Plz upload short cut method to find cube roots

    ReplyDelete
  12. Plz upload short cut methods to find cube roots...

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...