Thoughts on Ancient Egyptian Mathematics Kim R. W. Zahrt Communicated by: Dr. Micheal Kinyon Department of Mathematics abstract Do the experts, Egyptomologist, know the true history of Egypt, and furthermore, are they sure of the level of Egyptian mathematical thought? This paper demonstrates two problems found on ancient papyri, and examines the words of scholars to determine the answer to the above questions. It has been said that Egyptian mathematics was only practical arithmetic and simple geometry. There are several scholars who contend Egyptians lacked formal proofs and stated rules, and therefore they lacked \the scientic attitude of mind" (Gillings 232). Thomas Eric Peet, a noted professor of Egyptology, refers to the table of fractions in the Rhind Mathematical Papyrus as being proof that the Egyptians did not reach a scientic understanding of mathematics (ibid). Concerning geometry, Bartel L. Van der Waerdan in Science Awakening II states \The Egyptians of the Middle Kingdom had methods for calculating areas . . . but there is no textual evidence of a geometry with constructions and proofs. Furthermore . . . the mathematical texts were no longer copied after the Hyksos period" (41). These and other scholars contend that the Egyptians did not have the rigor of mathematics, and the value of studying Egyptian mathematics lies only in its place as history. I disagree. The rst question that comes to mind is, how did the Egyptians gure the labor, materials and plans for building the Giza Pyramids? This occurred almost six hundred years before the earliest known mathematical artifact, and shortly after the earliest known Egyptian writing. But even more interesting is that the Zoser step pyramids of Sakkara were built 200 hundred years before then (Gillings, Appendix 13). It is my contention that due to the enormous time span of ancient Egyptian history (cira. 4241 1785 B.C.E.) and the scarcity of very early mathematical artifacts, we can not be sure the Egyptians did not rise to a theoretical level of ability in mathematics. Isn't it possible they reached a high level of mathematical thought, and then settled into this pragmatic style which the experts submit? We must also keep in mind our own ethnocentric expectations concerning Greek style proofs and formulae. Perhaps the Egyptians viewed formulae as infered by example. If we continue to follow the suppositions of the experts, we will surely miss the clue that leads to the bases of Egyptian mathematical thought. There are two prime sources which are considered the best examples of Egyptian mathematics. These are the Rhind Mathematical Papyrus and the Moscow Mathematical Papyrus. Several other sources exist such as the the Kahun Mathematical Fragments and the Mathematical Leather Roll at the British Museum, but these add nothing of substance to our knowledge of ancient Egyptian mathematics. The author of the Rhind Mathematical Papyrus was an Egyptian scribe named Ah'mose in circa. 1552 B.C.E.. In the rst paragraph, he stated that his rendition was a copy of a papyrus made (circa. 1844 - 1797 B.C.E.) (Clagett 113). Please note how late in Egypt's development this occured. There is no indication of the extent of Egypt's theoretical development in the previous 2000 years. The Papyrus is a collection of practical mathematical problems and solutions which a scribe of that time would be expected to know. These math problems were originally numbered by A.A. Eisenlohr, a German Egyptologist, and that basic numbering scheme is well known today (Robbins 9). The Papyrus also includes several tables of fractions. The Egyptians primarily used unit fractions { one as the numerator and any natural number as the denominator 12 , 1 2 3 1 7 , 655 , etc., but included exceptions such as 3 and 4 . It 2 was as though the Egyptians had a preference for 3 since it was used in many of the problems and had its own symbol which was unrelated to 13 . Some argue that the Egyptians derived 31 from 23 , unlike today where 13 is inferred and then doubled to calculate 23 . The hieratic (the cursive form of the hieroglyphic) of 43 is seen on the Palermo Stone, but 43 was not used in known computations (Gillings 183). The Egyptians had no concept for zero and used no placeholder or decimal point (Robbins 11). On the Papyrus, red auxiliaries (red ink)were used as reference numbers similar to the modern use of natural number numerators (Gillings 81). Although earlier evidence of Egyptian mathematics exist, the Rhind Mathematical Papyrus is the source most frequently quoted as an example of classical Egyptian mathematics (Gillings 260-261). It was discovered as fragments, with some missing, in a building near the Ramesseum on the banks of the Nile River near Thebes in 1858, and it was then purchased by A. Henry Rhind. In 1865, after Rhind's death, the papyrus was sold to the British Museum. The Rhind Mathematical Papyrus is labeled BM 10057 and BM 10058 and is often referred to by these numbers. In 1922, additional fragments of the Rhind Mathematical Papyrus were found by P. E. Newberry (ibid). These are known as the Smith Fragments after Edwin Smith, who purchased them in 1862 - 1863 (Clagett 113). In 1877 Eisenlohr released a version of the text from pirated facsimiles originating at the British Museum. The British Museum nally released for publication the Rhind Mathe- Thoughts on Ancient Egyptian Mathematics matical Papyrus facsimiles in 1898. Peet penned his translation and documentary in 1923. This was followed with two volumes by Arnold Buum Chace, Chancellor of Brown University, during the period of 1927 to 1929 (Robbins 9). Other scholars have continued to analyze the Rhind Mathematical Papyrus. As recently as 1999, Marshall Clagett, Professor of History, Emeritus, at the Institute for Advance Study, Princeton, NJ, published a source book of ancient Egyptian science in which the aptly titled third volume, Ancient Egyptian Mathematics , apportioned a large part to the Rhind Mathematical Papyrus. Many math history classes study the documentation of this Papyrus because it is thought to be a good representation of the mathematical level of the ancient Egyptians and displays one of the earliest known forms of mathematics. The following is Problem 28 on the Papyrus. I use this particular problem because the steps used by the scribe produce the correct answer no matter what beginning number is used. Where as the think of a number problem was coined by Diophantus of Alexandria in the 3rd century C.E. (Gillings 181). I have used Chace's translation of the problem and will use Gillings' interpretation of Chace's translation as a guide in explaining Problem 28. Figure 1. Problem 28 as translated by A. B. Chace. Gillings, Richard J. Mathematics in the Time of the Pharaohs. The MIT Press. Cambridge (1975): 182. Figure 2. Gillings interpretation of Problem 28. (ibid.) 91 First notice the two lines over the 3 and the single line over the 10 in Gillings' modern interpretation (Fig. 2); these stand for 32 and 101 . A single line over the 3 stands for 31 . In modern mathematical notation this problem would look like this: Formula Pick a number X X + 23 X = Y Y - 13 Y = Z Z - 101 Z = X Example Let X = 27 (27) + 32 (27) = 45 (45) - 31 (45) = 30 (30) - 101 (30) = 27 = X The rst part shows how the problem is set up, and the second part is an example of how to solve the problem by replacing X with any variable (27 was used here). By working though the problem, the answer (27) is found to be the same as was started with. While it's not what we are use to seeing, it is easy to infer that this was an example of a general pattern that can be represented by a modern formula. The second most important document of Egyptian mathematics is the Moscow Mathematical Papyrus. W. S. Golenishchev, in a reply to L. S. Bull in 1927, tells of his purchase 1893 of the papyrus in 1892 3 or 4 . Clagett states that it is evident from this reply that the papyrus came from a tomb near the place where the Rhind Mathematical Papyrus was discovered. The rst time the Moscow Mathematical Papyrus was mentioned, it was merely noted by M. Cantor in 1894 in his Vorlesungen uber Geschichte der Mathematik , Vol. 1. B. A. Turae, the curator of the Moscow Museum in 1917, was the rst to analyze some of the contents of the papyrus (Clagett 205-206). The Moscow Mathematical Papyrus was broken down into 25 problems by W. W. Struve in 1930, although other formats are in existence (Clagett 207). Several of the problems are unreadable or unclear, but they seem to be of the same type as found in the Rhind Mathematical Papyrus. The 14th problem, the truncated pyramid, is probably studied more than any other problem on this papyrus. A truncated pyramid has a square base, and it tapers to a square top. In other words, a normal pyramid with the top cut o. Turae believed the Egyptians used a formula to nd the volume. In modern terms, it would be V = ( h3 )(a2 + ab + b2 ), where h is the height, and a and b are the sides of the corresponding squares. Clagett went on to say: The author [Turae] believed that, if his explanation of the problem was correct, it presented a new and interesting fact, that Egyptian mathematics yielded a problem not yet found in Euclid (207). Below I have used Clagett's translation to demonstrate Problem 14. K. Zahrt 92 multiply, corresponding to the Lines above from Clagett's translations. Using Line 4 of Col XXVII as an example: First they used two or more columns. In the right column they placed the multiplicand (4), then in the left column they placed the rst multiplier (1). They then doubled each multiplier going down the column, along with its corresponding multiplicand (they also were able to use 10, 12 , 2 1 3 , 10 as multipliers). When they found a combination of multipliers that added up to the original multiplier (4), they marked them with a \n" (in this case, it's just 4), then they added the right side numbers that corresponded (just 16 here, so Total = 16). This is similar to the binary systems used in computers today. Figure 3. The Truncated Pyramid Problem (Clagett 395-396). Note: the Egyptians read from right to left, so the rst part of the problem is on the right. The upper images which are facsimiles of the original are written in the hieratic, and the lower images are Clagett's translation into the hieroglyphic. Column XXVII: Line 4 1 4 2 8 n4 16 Total 16 Column XXVIII: Line 4 1 6 23 4 n 13 2 Total 2 Line 5 Line 4 1 n2 Total 1 2 n4 n8 n16 Total 4 8 8 2 4 8 16 32 56 Line 6 1 n2 Total 2 4 4 I have included these two example problems to show that the methods the Egyptians used to solve the problems can be universalized or used with any numbers. These point to possible theorems or functions. Figure 4. Clagett's Translation of Problem 14 (ibid. 221). Clagett's Translations simplied: [Col. XXVII] Line 1) States what is going to take place. Line 2) The height (h ) is established. Line 3) The lower (a ) and upper (b ) squares' sides are dened. Line 4) First square the lower side (a 2 ) which is 16 in the example. Line 5) It asks us to double the side a , but it is thought that this meant multiplying a by b . Line 6) Then square the upper side (b 2 ) which is 4. [Col. XXVIII] Line 1) Then, we are asked to add 16 Line 2) and 8 and 4 (a 2 + ab + b 2 ) Line 3) 28 is the result of this polynomial. Line 4) Next we take 13 of 6h which is 2, and multiply it by 28. Notice: h3 (a 2 + ab + b 2 ) Line 5) Lo and behold the answer. Next I have included the method that the Egyptians used to Many experts have examined Problem 14 on the Moscow Mathematical Papyrus, and several have tried using it to justify opinions that the Egyptians did not have an understanding of theoretical geometry. Clagett presents the theories of Gunn and Peet, Gillings, Van der Waerden, and R. Engelbach, to show how the Egyptians might have gured the volume of the truncated pyramids without the use of formulae (Clagett 83-90). The fact that many experts nd it necessary to prove the Egyptians used various practical methods (Peet thinks they made models in the mud fibid 88g) causes skepticism of their interpretations. Why else would they dwell on this simple problem? Clearly it is shown in Problem 14, Egyptians knew how to solve the volume given any parameters. A millennium had past from the time of these early papyri and the advent of the Greek culture. Notice that Diophantus is credited with naming the think of a number problems almost two thousand years after the Rhind Mathematical Papyrus presented one. It is interesting to note that in De vita Pythagorica Chapter 4, Iamblichos states that Pythagoras spent 22 years studying astronomy and geometry with the Egyptians. Furthermore, Van der Waerden states that we must choose not to believe Herodotus, Aristotle, Eudemos and Proklos in order to believe that Thales did not bring true geometry from the Egyptians to the Greeks (Van der Waerden 40-41). Does this sound like a civilization bounded by simplicity? Outside of the mathematical realm, there are other noted scholars of Egyptian history who have made comments that tend to lead one to doubt the opinions of the mathematical and science experts. Cyril Aldred in The Egyptians states, \The bureaucrat would also require [the scribe] to solve problems connected with such matters as the distribution of ration or seed-corn, the number of bricks required to Thoughts on Ancient Egyptian Mathematics build a given structure and the number of men . . ." (Aldred 90). Furthering this thought, James Henry Breasted in A History of Egypt stated, \Education thus consisted solely of the practically useful equipment for an ocial career" (Breasted 100). Is it not possible that by the time of the known mathematical artifacts, theoretical study was no longer valued? After all, almost 2000 years had elapsed since the beginning of Egyptian civilization. What would be the value of studying theory when the Egyptians already had methods that worked perfectly well? Fred Gladstone Bratton in A History of Egyptian Archeology comments, \In no other place can one see such evidence of high culture, such splendid examples of technical skill and artistry. Greece, the only rival, reckons her cultural history in centuries, but Egypt reckons hers in millenniums" (Bratton 25). Finally, John A. Wilson in The Culture of Ancient Egypt remarks: The idea of a rule-of-thumb pragmatism, with no trace of a reasoned and reasoning experimentalism, and the idea that a single word might mean both 'celestial glory' and mundane 'utility' are so foreign to modern thought that they should be argued more extensively.(Wilson 69) Much of the debate on the Egyptian's theoretical mathematic ability is based on conjecture. Van der Waerden, in the statement above, alludes to scarcity of ancient mathematical text with his words \no textual evidence." Struik suggests the same by using the phrase \available texts." Can our meager archeological ndings be the sum total of the Egyptian's knowledge of mathematics? I would rather doubt it. Egypt has survived conquerors, cultures, kings, pharaohs, and tomb robbers for over 3000 years and still ended up with the greatest library in the world at Alexandria. This refutes that they were interested only in the simple and practical. 93 It is important to note that the works we do have were found near the ancient government seats. Is it not possible that the ancient authors were employed by the government, and perhaps this practical style of mathematics was all that was needed by the bureaucracy? Recall that Turae believed the Egyptians solved the truncated pyramid problem which the Greeks did not. This problem could be a clue that the Egyptians had the ability to assess universal formulae. The sparse archeological evidence and the great span of Egyptian civilization fuel my continued doubts about the critics' views on the simplistic nature of ancient Egyptian mathematics. references Aldred, Cyril. The Egyptians. Revised and Enlarged Edition. New York: Thames and Hudson, Inc., 1984. Bratton, Fred Gladstone. A History of Egyptian Archeology. New York: Thomas Y. Crowell Company, 1969. Breasted, James Henry. A History of Egypt: From the Earliest times to the Persian Conquest. New York: Charles Scribner's Sons, 1937. Clagett, Marshall. Ancient Egyptian Science: A Source Book. Vol 1, Tome 1 & 2, Vol. 2 - 4. Copied for its Memiors Series by the American Philosophical Society. Philadelphia: 1999. Gillings, Richard J. Mathematics in the Time of the Pharaohs. The MIT Press. Cambridge (1975): 232. Robbins, Gay and Charles Shue. The Rhind Mathematical Papyrus. New York: Dover, 1987. Van der Waerden, Bartel L. Science Awakening II. Noordho International Publishing. Leyton, The Netherlands: Noordho International Publishing, 1974. Wilson, John A. The Culture of Ancient Egypt. Chicago: The University of Chicago Press, 1965. Kim is a junior majoring in Secondary Education with primary in Math and supporting in Physics with a Computer En- dorsement. He is scheduled to graduate in 2001. A version of this paper was written for M380, History of Mathematics. \I became interested in this topic after reading Neugebauer's opening sentence in A history of Ancient Mathematical Astronomy, Part Two, Book III, when he states, 'Egypt has no place in a work of the history of mathematical astronomy.' I thought, \Wow, this man is biased!"