# Yes !! I do not need a calculator :)

Question asked by Karishma Manwani in #Coffee Room on Feb 12, 2014

Karishma Manwani 路 Feb 12, 2014

Rank D1 - MASTER

I did not know that multiplying with 11 was this easy !

I came across a trick to multiply numbers with 11 and come up with your answer before the calculator .

For example : 32 * 11 [For numbers which add up to less than equal to 9]

Just add the two digits : 3+2=5 and place it in between the original number 32 and tada 352 is your answer 😀

99*11[Numbers which add up to a number greater than 9]

Add: 9+9=18

You again need to put this 18 in the middle of the original number but You have to add the 10s place number(obtained after addition) to the 1st digit of the original number .

(9+1)89 i.e 1089 is your answer

77*11

Answer : 847

Explanation : 7+7 = 14

Putting it in the middle : 7147

But you have to add 1 to 7 for the answer : (7+1)47 = 847

Start with this 2 digit number multiplication with 11 and display the MATHEMAGICIAN in you to your friends ! Enjoy 😀 Posted in: #Coffee Room

I came across a trick to multiply numbers with 11 and come up with your answer before the calculator .

For example : 32 * 11 [For numbers which add up to less than equal to 9]

Just add the two digits : 3+2=5 and place it in between the original number 32 and tada 352 is your answer 😀

99*11[Numbers which add up to a number greater than 9]

Add: 9+9=18

You again need to put this 18 in the middle of the original number but You have to add the 10s place number(obtained after addition) to the 1st digit of the original number .

(9+1)89 i.e 1089 is your answer

77*11

Answer : 847

Explanation : 7+7 = 14

Putting it in the middle : 7147

But you have to add 1 to 7 for the answer : (7+1)47 = 847

Start with this 2 digit number multiplication with 11 and display the MATHEMAGICIAN in you to your friends ! Enjoy 😀 Posted in: #Coffee Room

Bionic 路 Mar 11, 2014

Rank D1 - MASTER

56*11=(5+1)16=616..

Bionic 路 Mar 11, 2014

Rank D1 - MASTER

67*11=(6+1)37=737...

Bionic 路 Mar 11, 2014

Rank D1 - MASTER

34*11=(3(3+4)4)=374

smorgasbord 路 Apr 18, 2014

Rank D2 - MASTER

you could do a lot more than that with Vedic maths

Karthikeyan jaisankar 路 Jun 28, 2014

Rank C3 - EXPERT

47*11= (4+7)

=4117

=(4+1)17

=517 i got it"!!! 馃榾

=4117

=(4+1)17

=517 i got it"!!! 馃榾

Ramani Aswath 路 Jun 29, 2014

Rank A1 - PRO

The Trachtenberg Speed System of Basic Mathematics book was available in the IIT Madras library in 1962. Later I bought it and went through all of it. I still use the techniques when applicable.

Multiplication by 11 (any number of digits) is done by a process called add the neighbour. What is shown above is a special case of this.

The book is now available for free download.

https://www.scribd.com/doc/6422182/The-Trachtenberg-Speed-System-of-Basic-Mathematics

Also from here:

https://www.speed-math.com/download.htm

Multiplication by 11 (any number of digits) is done by a process called add the neighbour. What is shown above is a special case of this.

The book is now available for free download.

https://www.scribd.com/doc/6422182/The-Trachtenberg-Speed-System-of-Basic-Mathematics

Also from here:

https://www.speed-math.com/download.htm