And mathematicians divide by multiplying!
In formal definitions of arithmetics, division can be defined via multiplication: as a simplified example with real numbers, because a ÷ 2 is the same as a × 0.5, this means that if your axioms support multiplication you'll get division out of them for free (and this'll work for integers too, the definition is just a bit more involved.)
Mathematicians also subtract by adding, with the same logic as with division.