Wikimore

Summary

DescriptionStep Method Muliplication Algorithm.png	English: The image contains three diagrams and an explanation of my method of finding the product of two multi-digit number -- a method that does not require the use of the multiplication tables taught in school. That is, to use this method you do not need to know number facts such as "7x8=56". You only need to know how to add two numbers together or add a number to itself. It will be helpful, but not necessary, to know how to subtract a number from its own 10-multiple in place (without actually appending the zero) to compute the 9-multiple, and also helpful, but not necessary, to know how to divide the 10-multiple of a number by 2 to compute the 5-multiple without actually appending the zero. As far as I know it is my own "invention", but it is likely to have been "invented" before, but I could find no evidence of its ever having been previously published. (The final step of obtaining the product (by adding numbers on the diagonals) is the same as the final step of the "Lattice" method of multiplication, but that method requires the use of multiplication tables to fill in the rows.
Date	14 January 2016
Source	Own work
Author	LawrencRJ (Richard J. Lawrence)

Method is ideal for multiplying in a base other than ten using modular arithmatic.

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