Multiplication Of Eleven With Longer Numbers

 

Longer numbers are handled in the same way. The second rule, “ each successive number of the multiplicand is added to its neighbor at the right,” was used twice in the example above; in longer numbers it may be used many times. Take the case of 721,324 times 11:     7 2 1 3 2 4   x   1 1

First Rule: The last figure of 721,324 is put down as the right-hand figure of the answer:

7 2 1 3 2 4  x  1 1= _ _ _ _ _ 4

Second Rule: Each successive figure of 721,324 is added to its right hand neighbor: 7 2 1 3 2 4  x  1 1 =_ _ _ _ _ 64

                                                                                                                            7 2 1 3 2 4  x  1 1 = _ _ _ _ _564

                                                                                                                            7 2 1 3 2 4  x  1 1 = _ _ _ _4564

                                                                                                                            7 2 1 3 2 4  x  1 1 =  _ _ _34564

                                                                                                                            7 2 1 3 2 4  x  1 1 = _ _ _934564

Third Rule: The first figure of 721,324 becomes the left-hand figure of the answer:  7 2 1 3 2 4  x  1 1=_ _ _7834564

The answer is:7,934,564.

           Try one yourself: 441,362 times 11.