Multiplying by 12

Manjyot

Let’s take a look.
12 X 7

the first thing is to always multiply the 1 of the twelve by the number we are multiplying
by, in this case 7. So 1 X 7 = 7.

Multiply this 7 by 10 giving 70. (Why? We are working with BASES here. Bases are the
fundamentals to easy calculations for all multiplication tables. To find out more check out
our Vedic Maths ebook at http://www.memorymentor.com/big_brain.htm)

Now multiply the 7 by the 2 of twelve giving 14. Add this to 70 giving 84.
Therefore 7 X 12 = 84

Let’s try another:

17 X 12

Remember, multiply the 17 by the 1 in 12 and multiply by 10

(Just add a zero to the end):

1 X 17 = 17, multiplied by 10 giving 170.

Multiply 17 by 2 giving 34.

Add 34 to 170 giving 204.

So 17 X 12 = 204

lets go one more

24 X 12

Multiply 24 X 1 = 24. Multiply by 10 giving 240.

Multiply 24 by 2 = 48. Add to 240 giving us 288

24 X 12 = 288 (these are Seriously Simple Sums to do aren’t they?!)

Manjyot

How do we multiply by eleven easily?

First we will try this by writing the answer backwards.

So, when always multiplying a large number by 11, the last number will always be the last number of the sum we are multiplying.

EXPLANATION

176 is the number we are multiplying.

So the last number in out answer will be 6. If the sum was 143 the last number in our answer would be 3… get it?

So now what?

Easy, just add the next number to the last number, 7 + 6 = 13

So the next last number will be 3, carry the 1.

Add the 7 and 1 together, giving 8, then add the carried 1, 9 then write that number as our next part of the answer, 936

Then, the last number will be the first number in our sum, in this case 1.

So the answer is 1936.

Try 278

Last number is 8

7 + 8 = 15

Second last number is 5, carry the 1

7 + 2 = 9 add the carried 1, 10

Third last number is 0, carry the 1

Add the carried 1 to the first number in the sum, 2 giving:

2 + 1 = 3

So the answer is 3058!

Alternatively, you could always just add a zero to the number you are multiplying and then add the original number to it again…

156 X 11

try it this way:

Add a zero to the end

1560

Add 156 to this

1560 + 156 = 171