The first calculating machines for all four basic arithmetic operations appeared in the 18th century. They could be used to add, subtract, multiply and divide. In order to be able to multiply and divide with a machine, a number had to be stored. These mechanical number storage devices were often stepped rollers or pinwheels. We get to know both components and examine together how they work.

This program also deals with the further development of these so-called four-species calculating machines up to the Schubert pinwheel machines from 1969. The children can practise calculating all four basic arithmetic operations on these original calculating machines. When turning the crank, it quickly becomes clear - calculating with machines not only leads to the correct result. It's also fun.