Do you multiply this way!

Before my college days I used to multiply this way.
Image

But as time passed, I learned new things. In a Hindi magazine named “Bhaskar Lakshya”, I read an article in which a columnist ( I can’t remember his name) suggested how to multiply in single line (row). That was a magic to me.  I found doing multiplications this way, very faster – easier and smarter. There may be many who already know this method, but many others will be seeing it for the first time.

The ‘only’ requirements for using this method is the quick summation. You should be good in your calculations. Smarter your calculations, faster you’re.
I’ll try to illustrate this method below. If you had any problems regarding language (it’s poor off-course) and understandings, please feel free to put that into comments.

Let we try to multiply 498 with 753.
$ 4 9 8 \ \times 7 5 3$

Step I

Multiply 8 and 3 and write the unit digit of result carrying other digits for next step. The same is to be done with each step.
Image

Step 2

Image

Step 3

Image

Step 4

Image

Step 5

Image

The overall work looks like:
Image

I don’t know if there is any algorithm behind it. The pattern of calculation is very simple, which is making crosses and adding numbers.

 

You can use this method, multiplying larger numbers too. Try this one at your own. Steps are marked for convenience. :)

Thanks for Reading!

Gaurav Tiwari

Get useful blogging, marketing and learning resources, delivered to your mailbox once in a week.

With tools to help you learn, grow and earn better.
Get 4 exclusive e-books & templates for free to begin with. 🎁

You can either start a new conversation or continue an existing one. Please don't use this comment form just to build backlinks. If your comment is not good enough and if in some ways you are trying to just build links — your comment will be deleted. Use this form to build a better and cleaner commenting ecosystem. Students are welcome to ask for help, freebies and more. Your email will not be published or used for any purposes.

8 comments add your comment

  1. Hi Gaurav, I use this method as my primary method for multiplication, it really easy and works well. I never thought about the algorithm, but now as you noted there must be one, I just wrote it down. Here is it: Note that AB actually means 10a+b. e.gs.89=10×8+9
    (10x+y)(10a+b)
    =100ax+10bx+10ay+by
    =100ax+10(ay+bx)+by
    This is for multiplication of 2-digit number by 2-digit numbers; this can be proved for any number for that matter. This is precisely what we do!
    X Y
    x A B
    —————————
    AX (AY+BX) BY
    I don’t know who to do mathematical formatting in blogs, but I guess you will get it!

  2. Hi Gaurav, I use this method as my primary method for multiplication, it really easy and works well. I never thought about the algorithm, but now as you noted there must be one, I just wrote it down. Here is it: Note that AB actually means 10a+b. e.gs.89=10×8+9
    (10x+y)(10a+b)
    =100ax+10bx+10ay+by
    =100ax+10(ay+bx)+by
    This is for multiplication of 2-digit number by 2-digit numbers; this can be proved for any number for that matter. This is precisely what we do!
    X Y
    x A B
    —————————
    AX (AY+BX) BY
    I don’t know who to do mathematical formatting in blogs, but I guess you will get it!

    • Great work!! :)
      Now, I should reopen my mathematics books. :D

    • Great work!! :)
      Now, I should reopen my mathematics books. :D

Leave a Reply

%d bloggers like this: