Appendix 3: Intro to Egyptian Mathematics

!!! This appendix is not nearly done yet and we’re just moving pieces here as they seem appropriate. !!!

Multiplication notation

Infrequently in Middle Egyptian a number symbol would be written above a number of ones marks (or occasionally other symbols) and produce a more multiplication-based notation. This could produce numbers over one million:

 𓆐 𓂭
𓐀𓏼
7×100,000 + 3×10,000 = 730,000

𓆐
𓍢𓏺
101×100,000 = 10,100,000

Fractions

In general, Egyptian fractions could be written by putting 𓂋‌ r above a number: 𓂋‌𓍤 ¹⁄₃₀₀. A few basic fractions had special symbols: 𓐞 ½ (transl. gs), 𓏴 ¼ (also written 𓂋‌𓏽) , 𓂌 ⅔ (rwj), 𓂍 ¾ (ḫmt-rw).

The Egyptians could only write unit fractions, that is fractions with 1 for a numerator (except for ⅔ and ¾). For any other fraction with a higher numerator, it had to be split into multiple fractions: to write ²³⁄₅₀, one must expand it into unit fractions:

²³⁄₅₀ is more than ⅓ but less than ½, so we take ⅓ from it;
²³⁄₅₀ – ⅓ = ⁶⁹⁄₁₅₀ – ⁵⁰⁄₁₅₀ = ¹⁹⁄₁₅₀, which is a bit more than ⅛, which we take from it;
¹⁹⁄₁₅₀ – ⅛ = ⁷⁶⁄₆₀₀ – ⁷⁵⁄₆₀₀ = ¹⁄₆₀₀.

So our total is ⅓ + ⅛ + ¹⁄₆₀₀ and would be written 𓂋‌𓏼𓂋‌𓐁𓂋‌𓍧. A lot of the Rhind Mathematical Papyrus is dedicated to expanding fractions.

Table of cardinal and ordinal number words

NumberCardinal (masc.)Cardinal (fem.)Ordinal (masc.)Ordinal (fem.)
1𓌡𓂝‌𓏤 wꜥ𓌡𓂝‌𓏏𓏤 wꜥ𓁶𓊪𓏭 tpj𓁶𓊪𓏏 tpt
2sn.wwj1sn.t𓌢‌𓈖𓏌‌𓅱‌𓏻 sn.nw𓌢‌𓈖𓏌‌𓅱‌𓏏𓏻 sn.nwt
3ḫmt.wḫmt.tḫmt.nwḫmt.nwt
4jfd.wjfd.tjfd.nwjfd.nwt
5dj.wdj.tdj.nwdj.nwt
6sjs.wsjs.tsjs.nwsjs.nwt
7sfḫ.wsfḫ.tsfḫ.nwsfḫ.nwt
8ḫmn.wḫmn.tḫmn.nwḫmn.nwt
9psḏ.wpsḏ.tpsḏ.nwpsḏ.nwt
10mḏwmḏtmḥ-10mḥt-10
11mḏw-wꜥmḏw-wꜥt(etc.)2(etc.)
12, … 19mḏw-sn.wwj, etc.mḏw-sn.t, etc.
20mḏwtjmḏwtt
30mꜥbꜣmꜥbꜣt
40ḥmw3
50djjw
60sjsjw
70sfḫjw
80ḫmnjw
90psḏjw
100št
200štj
1000ḫꜣ
10,000ḏbꜥ
100,000ḫfn
1,000,000ḥḥ
1. For 2-9, dots separate roots from endings, since for those numbers, the ordinals are formed from the roots of the cardinals.
2. For all numbers above 9, the ordinal is mḥ or mḥt followed by the cardinal.
3. Cardinal tens from 40-90, and higher numbers except 100 and 200, have masculine only. 100 and 200 have feminine only.

As noted, the Egyptians rarely wrote the names of their numbers out, although they’ve been reconstructed as somewhat similar to English: ḫꜣ sfḫw-št ḫmnjw-psḏw “one thousand, seven-hundred, eighty-nine”. Note that all the components with two forms used the masculine (sfḫw-št, not *sfḫt-št) except the very last one, which could take the feminine form if it had one, if describing a feminine noun: ḫꜣ sfḫw-št ḫmnjw-psḏt.

The cardinals from 11 to 19 are compounds: mḏw-wꜥ … mḏw-psḏw “ten-one … ten-nine”. “200” had its own word štj listed above, but 2000 and 20,000 are compounds in reverse order: ẖꜣ snwwj, ḏbꜥ snwwj, probably because snwwj started out as a dual. The fact that 10,000 has its own word separate from 1000 means that large numbers get compounded differently: 120,000 is not “one hundred twenty thousand”, but “twelve ten-thousand”: mḏw-snwwj ḏbꜥ.

The glyph for “million” is the god ḥḥ Heh, god of infinity, but the number “one million” was possibly pronounced št ḏbꜥ “a hundred ten-thousands”, and so on: ḫmtw-št ḏbꜥ “three million”, literally “three hundred ten-thousands”.