The nazbalum, a number related to brick deliveries and earth transportation,
appears in Old Babylonian period (2018-1595 BCE) coefficient lists, while its use is implicit in mathematical texts of this period that present brick deliveries. As we will see, earlier explanations of the nazbalum, in so far as brick deliveries are concerned, have defined it as based on a quantity of bricks transported over a month-long period or limited by an order of magnitude in another way. A study of this coefficient’s use in mathematical texts will show that the nazbalum is not based on a quantity of bricks but is instead a coefficient used to define daily work and, while it may appear on first inspection to be a fixed product of the distance multiplied by the number of bricks, it is always represented as a floating number in the coefficient lists and, as will be shown, this allows for flexibility in interpretation and use. Moreover, because the nazbalum is a floating number it is never expressed using any numeric system that expresses fixed quantities. Finally, the word nazbalum only appears explicitly in coefficient lists. Outside of this context, any reference is only implicit