A 2,000-year-old Chinese grain riddle predates Gaussian elimination
The 'Nine Chapters on the Mathematical Art' poses this: three sheaves of a good crop, two of mediocre and one of bad together yield 39 measures of grain; two good, three mediocre and one bad yield 34; one good, two mediocre and three bad yield 26. How many measures of grain does one sheaf of each grade hold?
Reveal the answer
One sheaf of good grain holds 9¼ measures, mediocre holds 4¼, and bad holds 2¾. The text's method, arranging the coefficients into a grid and eliminating them column by column, is functionally identical to Gaussian elimination for solving simultaneous equations, roughly 1,800 years before Carl Friedrich Gauss's name got attached to it in the West.