1) prefix the number to be multiplied by zero .

2)The figures in the answer is obtained by adding the units place of number (11-19) with the each figure of the number to be multiplied and adding the sucessive number to it.(this shuold be done similar to our multiplication from right to left)

Example:

234X11

1) add zero in front of 234 ------------- 0234X11

2) the digit in units place of 11 is one and digit sucessive to 4{right most) is zero

So do the following (4X1)+0 = 4 0234X11

4

Now move towards left ,next digit is (3X1)+4 =7 0234X11

74

Now move towards left ,next digit is (2X1)+3 =5 0234X11

574

Now move towards left ,next digit is (0X1)+2 =2 0234X11

2574

Isnt it easy and cool?