RULES OF EGYPTIAN NUMBERS - HISTORY - 2025

The Egyptian numbers correspond to one of the oldest numbering systems known to mankind.

Devised approximately 3000 years ago, they were grouped in a base 10 system, like the decimal system that is currently used in the world, although with some differences.

It was a non-positional system, which means that the position of a digit in a number did not affect its value.

Instead, the symbols were repeated as many times as necessary regardless of the sense of the writing. In this way, numbers from units to several million could be represented.

Rules of the Egyptian numbering system

Although it is considered a decimal base system because it uses the powers of 10 for numerical representations, it was actually based on 7 digits, which were assigned to one, ten, one hundred, one thousand, ten thousand, one hundred thousand and one million / infinity..

There were two ways to write the numbers: by name or by value. The current equivalent would be to write "Twenty" or "20".

The name of the numbers was more complicated and rarely used when performing mathematical operations.

Unlike the current decimal system, where the further to the left a figure is within a number, the more its value increases, when writing in Egyptian numbers there is no specific order.

If, for example, we assign the letter D the value of 10, and the U the value of one, writing the number 34 according to the Egyptian system would be: DDDUUUU.

Similarly, as they are not governed by position, 34 can be written: UUUUDDD or DDUUUDU, without affecting its value.

Operations in Egyptian numbers

The Egyptian numbers allowed to carry out the elementary operations of arithmetic, that is, addition, subtraction, multiplication and division.

Add and subtract

The addition was as simple as writing a larger number with the symbols for the addends. Since these could be in any order, it was enough to rewrite them.

When a symbol was repeated more than ten times with respect to its superior, ten of these were erased and the superior was written.

The easiest way to see this is to imagine that after adding there were twelve “Ones” left. In that case, ten of these were deleted and replaced by a "Ten" and two "Ones."

In subtraction, the elements were subtracted from one side with respect to the other and decomposed if necessary. To subtract "7" from "10", both had to be expressed in "Ones".

Unlike the plus (+) and minus (-) signs currently used, Egyptian numbers used a symbol similar to walking legs, the subtraction or addition was given by the direction in which they were going.

Multiplication and division

Both multiplication and division used the method of multiplication by doubling, where one of the numbers is written on one side and a one on the other. Both begin to duplicate until they find an equivalence.

It required very good handling of addition and great mental and visual ability, so knowing how to multiply in ancient Egypt gave talented mathematicians a certain kind of prestige.

References

1. Egyptian numbers (July 18, 2015). Retrieved on November 15, 2017, from Locura Viajes.
2. J. O'Connor, F Robertson (December 2000). Egyptian numerals. Retrieved on November 15, 2017, from History MCS.
3. Luke Mastin (2010). Egyptian Mathematics. Retrieved on November 15, 2017, from Story of Mathematics.
4. Egyptian numbering system (March 20, 2015). Retrieved on November 15, 2017, from Mathematics for you.
5. Egyptian method of multiplication (August 25, 2014). Retrieved on November 15, 2017, from Mate Melga.
6. Alexander Bogomolny (nd). Egyptian Multiplication. Retrieved on November 15, 2017, from Mathematics Miscellany and Puzzles.