Of Ethopian and Egyptian Multiplication
A long time ago, maybe when I was in second standard or so, a teacher told me about this Egyptian Multiplication method. Suppose you wanted to multiply 14 with 23. You keep halving one, and doubling the other.
Double Halve
14 23
28 11
56 5
112 2
224 1
Now simply add the numbers in the double column which have an odd parter in the halve column. That would be 14+28+56+224 = 322. And voila, 14 * 23 is indeed 322.
It used to amaze me quite a bit as a kid. I could multiply huge numbers with relatively small numbers, by just knowing how to halve and to add. In fact, as a result, I pushed off learning the two digit multiplication “method” – till, I was forced to by my mother 
.
I forgot about it by the time I was in the fifth I think, till I came across it here. I was thinking about it again, when it struck me. I was just multiplying in binary . I had come a full circle .
Try reasoning about some of the other ways in that post and the next. Makes for some fun thinking.
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