**Nicolas Chuquet**describes himself as a Parisian and says that he is a bachelor of medicine. We do know that he moved to Lyon in around 1480 since his name appears in the Lyon tax registers of the time. For example in the registers of 1485 and 1487 he is described as "Nicolas Chuquet, algoriste".

Very little else is known about his life except that he earned his living as a copyist or writing master. Evidence of Italian links in his writings could indicate that he had visited Italy, but it is equally possible that these links come from the large Italian community living in Lyon at the time Chuquet lived there.

Chuquet wrote an important text *Triparty en la science des nombres*. This is the earliest French algebra book although for some time La Roche was thought to have written the first French algebra. Chasles pointed out, in 1841, that La Roche's work held this distinction, but also pointed to a lost work of Chuquet as being earlier. When Chuquet's manuscript was found it was seen at once that La Roche had copied Chuquet's *Triparty en la science des nombres*. The manuscript of *Triparty en la science des nombres* even contained annotations in La Roche's handwriting.

The *Triparty en la science des nombres* covers arithmetic and algebra. It was not printed however until 1880 so was of little influence. The first part deals with arithmetic and includes work on fractions, progressions, perfect numbers, proportion etc. In this work negative numbers, used as coefficients, exponents and solutions, appear for the first time. Zero is used and his rules for arithmetical operations includes zero and negative numbers. He also uses *x*^{0} = 1 for any number *x*.

The sections on equations cover quadratic equations where he discusses two solutions.

**Article by:** *J J O'Connor* and *E F Robertson*