If

    A × B = C 

then

    log A + log B = log C

And if

    D^E = F

then

    E × log D = log F

Mostly a tongue in cheek comment but if you don't know log rules at all check out log tables [0]. And you'll see that if you use log values then multiplication and division become addition and subtraction and equally simply.

Relies on you either having stored the needed data or efficiently calculating logirithms and antilogirithims.

https://www.cuemath.com/algebra/log-table/