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
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.
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.