Page:The Rhind Mathematical Papyrus, Volume I.pdf/99

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38]
SECTION VII—DIVISION OF A HEKAT
83

Proof of the result expressed in this form.

1 14116 hekat 123111122166 ro
2 1218 " 312111133166 "
17 132 " 412122 "

The total of the larger portions of these products makes
121418116132164 hekat 423ro,

or 31923ro.

The smaller fractions
111111122122133166166 taken as parts of 66, are equal to 6633211.
The total is 22, which is 13 of 66, and this with 319 % makes 320 ro or 1 hekat, as it should.

There are some peculiarities here in the numerical work. Thus in multiplying 317 so as to get 1, the author starts by saying that 122 of 317 is 122, and his explanation, written on one side, is literally, "The making it is of 17 times 22 to find 317." Also a little further along, in proving his answer, 16111122166, multiplying it by 317, he writes as one step, 17 122, and explains it by saying in almost the same words, "The making it is of 122 times 7 to find the fraction above." It is as if he were familiar with the relation of the three numbers 7, 317 and 22. Possibly he had this relation in some table; or in some previous reckoning he had multiplied 7 "for the finding of 22," which would give him at once 317. Then he would know that 17 of 22 is 317, that 122 of 317 is 17, and that 122 of 7 is the same as the result of "getting 1 by operating on 317" that is, it is the number that he gets in this solution, 16111122166, so that, finally, 17 of the last expression is equal to 122.[1]

The fractional expressions in the solution and different proofs are quite complicated and it is possible that he applied them to 66 each time that he had additions to make, but, except in the last case, there is no indication of this.

In the first proof he doubles 16111122166 and gets 12111133156. Here twice 16 is 13, twice 111 16166 (by the table at the beginning) and the 13 and 16 make 12 finally, twice 122166 make 111122 In a very similar way in the second and third proofs he doubles the fractional expression 23111122166

In working out the expression of the result in ro he has 111 of 320 equal to 29111, and in the proof which follows, 17 of 101 23111122166 is given as 141212; also in the last proof 17 of 14116. hekat 123111122166 ro is given as 132 hekeat 412122 ro. These are more difficult than most of the divisions in the papyrus. and the author does not state explicitly how he performed them.

  1. See Introduction, page 5, footnote 2.