Counting skill, in this case the Polish nobility's skill in the 16th century, has escaped the attention of historians of economy and culture, but disregard of this subject can call into question our analyses and evaluations of how the noblemen managed their affairs. The study below is based on an analysis of accounts, made by the first inspection in Little Poland, a document produced by a commission composed of three noblemen who took full responsibility for the financial aspect of their inspection. In order to evaluate the inspectors' competence some 7,000 accounts have been taken into consideration. The results of the inspection in Lublin palatinate, which contained 1,009 evaluations and calculations -additions, deductions, multiplications, and divisions - as well as re-counts of prices and measures, have been examined in great detail. The analysis has shown 14 mistakes in counting (1.4%) but there were in fact only six obvious mistakes (0.6%) if we eliminate copying errors and the fact that the endings of figures were sometimes rounded off. As a rule the mistakes were small, with the exception of one serious error when the cost of the personnel was not deducted from the income, but this was discovered and corrected by one of the inspectors. This would indicate that the inspectors were competent in counting; they could even assess fluctuating prices and calculate what profits would be derived from future investments or re-organisation. It is impossible to say to what extent the results can be generalised for there are no studies on this subject.