Ethiopian Math
Ethiopian
tribesmen can only double or halve numbers - by using pebbles as counters. By halving and
doubling, they take any two numbers, multiply them and come out with the right answer.
For example, if a tribesman wants to buy 13 sheep at 15 Ethiopian dollars each, here's how
he works it out...
Put 13 in a left column, and 15 in a right column. Halve the left figure - you get 6
1/2... ignore the 1/2 (Ethiopians don't know anything about fractions). Double the
right-hand figure. Keep this up until the left-hand figure is 1. You should now have:
13 15
6 30
3 60
1 120
Even numbers in the left column are evil to the superstitious tribesmen, and must be
destroyed - together with their guilty partners. So scratch out 6 and its partner 30. Now
add the right-hand column and you have the correct answer: 195. Try this with any two
numbers - it doesn't matter which side is halved or doubled - the answer is always right!
The Ethiopian's primitive mind simply cannot grasp how our system works. Of course you see
at once how this joe-k works... Or do you?