Multiplying a 2 Digit Number by 11 | Mental Mathematics for Class 8 PDF Download

This technique teaches jrouhowto multiply any number by eleven, easily and quickly
We will take a few examples and from these yju will see the pattern used and also how easy they are to do.
So, to begin let’s try 12 time 11.
First things first yju will ignore the 11 for the moment and concentrate on the 12.

Split the twelve apart, like so:
1<-------->2
Add these two digits together 1+2 = 3
Place the answer, 3 inbetweenthe 12 to give 132

11X12 = 132

Let’s try another:
48 X 11
again, leave the 11 alone for a moment and work with the 43
4 + 8 = 12
So now we have to put the 12 in between the 4 and 8 but don’t do this: 4128 as that is wrong.
First, do this: Place the 2 from the twelve in between the 4 and 8 giving 428.

Now we need to input the 1 from the twelve into our answer also, and to do this just add the one from 12 to the 4 of 428 giv ing 528.
Ok, one more
74X11
7+4 = 11
7 (put the 1 from the right of 11 in) and 4 then add the 1 from the left of 11 to the 7
74 X 11 = 814

This trick is much simpler than the previous one and it is more useful too. Let the number be 27 .
Therefore 27 × 11
Divide the number as 2 _ 7
Add 2+ 7 = 9
Thus the answer is 297
Wasn't this one simple. But there is one complication. If you take a number like 57 Thus _57 x 11
Divide the number as 5 _ 7
Add 5 + 7 = 12
Now add 1 to 5 and place 2 in the middle so the answer is 5+1_2 _7 = _627
Thus the answer is 627