The Ancient Egyptian understanding of fractions seems to have been rather
different from our own. They understood the idea of unit fractions
(those of the form 1/n), but do not seem to have formulated the notion
of a general fraction of the form m/n, except in certain special cases.
All fractions except 2/3 were thought of as sums of unit fractions, Bearing
in mind that multiplication and division were carried out by repeatedly doubling
numbers, it was important to be able to calculate the double of any useful
unit fractions, and indeed the Ahmes Papyrus opens with a table
expressing fractions of the form 2/n as a sum of unit fractions, for all
odd values of n from 5 to 101.
When writing unit fractions, they would place the open mouth
symbol
above the symbols for n. For example, the hieroglyphs for 1/4, 1/10,
and 1/101 were
1/4
1/10
1/101
The symbol for 2/3 was rather unusual by today's standards, in that it may have designated
one divided by one-and-a-half, and was written
.
This fraction was very important to the Ancient Egyptians, so much so that
the standard technique for finding one third of a given number was first
to calculate two thirds of the value, and then halve the answer.
above the symbols for n. For example, the hieroglyphs for 1/4, 1/10,
and 1/101 were
.
This fraction was very important to the Ancient Egyptians, so much so that
the standard technique for finding one third of a given number was first
to calculate two thirds of the value, and then halve the answer.
