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First take two numbers that you want to multiply and place them at the top of two adjacent columns. Divide the number in the left-hand column by two. Ignore any remainder and write the new number beneath the first.
Repeat the step until you are left with 1. Now double the number in the right-hand column and write the answer below it. Keep doubling all the way down until there are equal numbers of figures in both of the columns.
Delete the numbers in the right-hand column that are next to even numbers in the left-hand column.
For example:
9 x 8 = 72
4 16 (delete)
2 32 (delete)
1 64
Now add up the remaining numbers in the right-hand column and you will find that the total equals the result of multiplying the two original numbers at the head of the lists. Why?
Find out in this week's Last Word section. Happy Christmas.
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