Mathematical knowledge and practices in Ancient Mesopotamia vary according to the milieus under consideration. This paper deals with the numerical data—prices and wages—used in texts produced in different contexts and for different purposes. It focuses on the corpus of the kingdom of Larsa (Tell es-Senkereh), in southern Mesopotamia, for which we have a large number of texts of various genres for the Old Babylonian period (twentieth-eighteenth centuries BCE). Three different types of texts that mention prices and wages are taken into account: royal inscriptions, mathematical texts and administrative texts. A comparison between prices and wages recorded in royal inscriptions and those provided by administrative and economic texts show that kings wanted to control prices and claimed to pay high wages to their workers, by providing data which are different from those found in texts of practice. In contrast, collections of laws reflect the determination of the sovereign to act as a just king. The numerical values mentioned in these texts are similar to those in the administrative texts and the mathematical texts which also rely on real numerical values. Since mathematical problems were inspired by the organization of the work for large construction projects ordered by kings at the end of the third and beginning of the second millennia BCE, they also rely on real numerical values.