How to write fractional expressions

A fractional expression is an expression using two or more unit fractions
e.g. /2 / 5 /10=a half + a fifth + a tenth

The Conventions

The following conventions, which can be observed in the Rhind Papyrus and other mathematical papyri, were followed by the Ancient Egyptian scribes when writing fractional expressions:

1. When a fraction can be expressed in more than one form, use the form which requires the least number of unit fractions.
2. Always use the largest unit fraction possible unless this means that the previous rule cannot be complied with.
3. In a fractional expression, no unit fraction may be used more than once.
4. Write the unit fractions in decreasing order of size.

(Refer to Number System for basic fractions)

A few examples should make these easier to understand.

1. The fraction 3/4 could have been written by a scribe as /2 /4 or /3 /4 /6. The shorter expression was always used.
2. The fraction 7/12 could have been written as /2 /12 or /3 /4. The scribe would have used /2 /12 as uses the larger unit fraction, /2, which is bigger than /3.
3. The fraction 9/10 would not have been written as /2 /5 /5 because each unit fraction could only be used once in an expression. So 9/10 would have been written as //3 /6 /30.
4. The above example of 9/10, written as //3 /6 /30, shows the unit fractions being written in descending order of size i.e. //3 > /6 > /30.