《孫子算經卷下》 "Sun Tzŭ's Computational Classic: Volume III"
§34. Powers of 9

This section gives a word problem asking for powers of 9.

Translation

Chinese source text: Version A, Version B, Version C, Version D.
Unless noted otherwise, I follow the text from Version D, 《知不足齋叢書》本.

Source text Target text Notes
今有出門望見九隄、隄有九木、木有九枝、枝有九巢、巢有九禽、禽有九雛、雛有九毛、毛有九色。 Suppose there be [a] going out [the] entrance, looking [and] seeing nine embankments, [each] embankment having nine trees, [each] tree having nine branches, [each] branch having nine nests, [each] nest having nine fowls, [each] fowl having nine chicks, [each] chick having nine feathers, [each] feather having nine colours.
問各幾何。 [We] ask, how many [be] each?
答曰、木八十一、枝七百二十九、巢六千五百六十一、禽五萬九千四十九、雛五十三萬一千四百四十一、毛四百七十八萬二千九百六十九、色四千三百四萬六千七百二十一。 Answer saith: [the] trees eighty-one; [the] branches seven hundred [and] twenty-nine; [the] nests six thousand five hundred [and] sixty-one; [the] fowls five myriad nine thousand [and] forty-nine; [the] chicks fifty-three myriad one thousand four hundred [and] forty-one; [the] feathers four hundred [and] seventy-eight myriad two thousand nine hundred [and] sixty-nine; [the] colours four thousand three hundred [and] four myriad six thousand seven hundred [and] twenty-one.
  • In modern notation,
    \begin{aligned} 9^2 &= 81 && \text{(trees)} \\ 9^3 &= 729 && \text{(branches)} \\ 9^4 &= 6561 && \text{(nests)} \\ 9^5 &= 59049 && \text{(fowls)} \\ 9^6 &= 531441 && \text{(chicks)} \\ 9^7 &= 4782969 && \text{(feathers)} \\ 9^8 &= 43046721 && \text{(colours)}. \end{aligned}
術曰、置九隄、以九乘之、得木之數。 Method saith: put [down the] nine embankments; multiplying it by nine, resulteth in [the] number of trees.
又以九乘之、得枝之數。 Again multiplying it by nine, resulteth in [the] number of branches.
又以九乘之、得巢之數。 Again multiplying it by nine, resulteth in [the] number of nests.
又以九乘之、得禽之數。 Again multiplying it by nine, resulteth in [the] number of fowls.
又以九乘之、得雛之數。 Again multiplying it by nine, resulteth in [the] number of chicks.
又以九乘之、得毛之數。 Again multiplying it by nine, resulteth in [the] number of feathers.
又以九乘之、得色之數。 Again multiplying it by nine, resulteth in [the] number of colours.

Cite this page

Conway (2023). "Sun Tzŭ's Computational Classic: Volume III §34". <https://yawnoc.github.io/sun-tzu/iii/34> Accessed yyyy-mm-dd.