Origin or author of 'Japanese Multiplication Method'

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What is the origin or author of the method ¹ shown in the following image?

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Notes

1. Also known as Japanese Multiplication Method for Kids.

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2 Answers

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According to Wikipedia, "It is not known where it arose first, nor whether it developed independently within more than one region of the world".

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This method is just breaking up the numbers into their tens, hundreds, and so on so that you can keep track of place values when multiplying. In this example, $$15*23=(10+5)*(20+3)=20*10 + 5*20 + 10*3 + 5*3=200 + 130 + 15$$ So the first digits of each number 1 and 2 correspond to 10 and 20 which when multiply to give the largest place value, the mixed terms are in between and the last digits 5 and 3 give the smallest contribution. So basically, the method is using distributivity and is not very different from other methods. It does nicely keep track of powers of 10.

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