Printing calculators

These machines are more than simple adding machines: they can also multiply and divide. Their main advantage over rotary calculators is in their printed record of all calculations, reducing the need to repeat calculations to check their accuracy, and potential errors when copying from dials. Later developments brought the speed and capacity of the printing calculator up to the level of rotary calculators, and some had features not available on rotary calculators.

The mechanical printing calculator survived in the marketplace a few years longer than the rotary calculator, primarily due to the fact that the printing function still required considerable mechanical complexity, even in an electronic calculator.