Magic Number 9 – Multiplying with 9’s


“How can I make math fun for my boys” is always an ongoing task for me as it always keeps them engaged and interested in math. They actually look forward to these games and are equally curious to understand and solve the mystery of Math.  How boring it would be if you have to do the same math worksheets every day.  In the next couple of days, I would be sharing all the math tricks and games I use to teach my kids with my blog friends, so stay tuned.

Today I would show you a quick and fail-proof method of multiplying with 9’s. The number 9 is a magical number, any mathematical calculations done with this number would produce some interesting numerical patterns.  

To multiply a number N with 9’s, divide the result into two sections – the left section and the right section. The left section would be ( N-1 ) and the right section would be ( 9’s – N ) +1 .

For example,   4576 × 9999  = 45,755,424. The left section of the result would be the number 4576 – 1 = 4575 and the right section would be 9999 – 4576 = 5423 and adding 1 to it which would be 5423 +1 = 5424.

Let’s try with some other number, may be  853. So, if multiplying 853 x 999 = 852,147. The left section of the result would be 853 – 1 =  852 and the right section would be 999- 853 +1 = 147.

So, leave your calculators aside and have fun multiplying large numbers with 9’s in a fraction of a second and don’t forget to like my page if you would like to be remain updated with all the new exciting posts.

Happy Calculating !


Leave a Reply

Your email address will not be published. Required fields are marked *