In this section will be examined some calculating tools, used by mankind in the past 2000 years. Of course we will start with the abacus, the most famous and of longest use calculating tool. Then will be examined two of the inventions of the Scottish noble John Napier—Napier's bones (Napier's rods) and the logarithms. In the section Gadgets will be examined all sorts of calculating tools, which are not so complex, to be included in the section of the calculating machines.