MULTIPLICATION BY NINE

1.Subtract the right –hand  figure of the long number from ten. This gives the right-hand figure of the answer.

2. Taking each of the following figures in turn, up to the last one, subtract it from nine and add the neighbor.

3. At the last step, when you are under the zero in front of the long number, subtract one from the neighbor and use that as the left-hand figure of the answer.

Of course, in all these steps it is understood that is there is a dot ( a carried one), you have to add it in as usual.

Here is an illustration of how it works out:8,769 times 9.

                    0 8 7 6 9    x     9

                    7 8 9 2 1

First: Take the 9 of 8,769 from 10, and we have the 1 of the answer.

Second:Take the 6 from 9 (we have 3) and add the neighbor, 9 ; the result is 12, so we write a dot and 2.

Third: 7 from 9 is 2, the neighbor (6) make it 8, and the dot makes  it 9.

Fourth: 8 from 9 is 1, and the neighbor makes it 8.

Fifth: This is the last step; we are under the left-hand zero. So we reduce left-hand figure of 8,769 by one, and 7 is the left –hand figure of the answer.