Page:The Algebra of Mohammed Ben Musa (1831).djvu/203



In the formation of the numerals, the thousand is not, like the ten and the hundred, multiplied by the units only, but likewise by any number of a higher order, such as tens and hundreds: there being no special words in Arabic (as is the case in Sanscrit) for ten-thousand, hundred-thousand, &c.

From this passage, and another on page 10, it would appear that our author uses the word عقد, plur. عقود, knot or tie, as a general expression for all numerals of a higher order than that of the units. Baron S., in his Arabic Grammar, (vol. 1. § 741) when explaining the terms of Arabic grammar relative to numerals, translates عقود by næuds, and remarks: Ce sont les noms des dixaines, depuis vingt jusqu’à quatre-vingt-dix.

The forms of algebraic expression employed by are thus reported by  (Origine, &c. dell’ Algebra, I. p. 1.): ''Tre considerazioni distingue Leonardo nel numero: una assoluta, o semplice, ed è quella del numero in se stesso; le altre due relative, e sono quelle di radice e di quadrato. Nominando il quadrato soggiugne, ed il nome di censo è quello di cui in seguito si serve. That seems to have chosen the expression census'' on account of its acceptation, which is correspondent to that of the