Ethiopian Math is Different Than Yours

Thanks to still lurking on some old college panlists, I recently discovered a fascinating thing about Africa! Ethiopia, specifically. Ethiopia is actually one of my favorite countries in Africa, for a variety of reasons, including that it is one of only two countries that was never colonized. Also famous for its coffee, Haile Selassie, Communist massacres in the 1970s, an extremely good-looking populace, and possibly the origin of Christianity. The Prime Minister died last month and that's also been in the news.

Ethiopian woman, browncondor.com

Ethiopia is less famous for--its MATH! That's right, Ethiopian math is different from American math. Let's see how Ethiopian multiplication works...

Ethiopian Multiplication

Say you want to multiply two numbers, 23 and 17, but you don't know American multiplication.

23   17

Halve one of the numbers (let's do 23), ignoring any remainder, and double the other (17).

23      /    17
halve / double
11     /    34
5      /     68
2      /     136
1     /      272

Add the numbers on the right that are across from odd numbers on the left (so not 2     /     124).
17 + 34 + 68 + 272 = 391

Guess what 23 X 17 = ?

Ethiopian Multiplication = American Multiplication
391 = 391

BBC explaining how it all works:
http://www.youtube.com/watch?feature=player_embedded&v=Nc4yrFXw20Q#!

Random Kate Thoughts: We forget sometimes that a lot of the math we use came from Africa. Timbuktu, Mali, was the home of Black Islamist scholars developing sophisticated math, astronomy, and sciences back in the Middle Ages. We ALSO think that our way of math is the "only" way of doing math. Ethiopian multiplication (also sometimes known as Egyptian multiplication) is just as accurate as ours, but ignores fractions and remainders. Sometimes Africa amazes me. And next time you don't feel like doing long multiplication... try some Ethiopian math.