I actually tried to do multiplication on the NES, using some manner of shifts, though a loop would accomplish the job (slowly). (like 6x5 = 6x4 + 6x1 = (6 left-shift 2) + 6 instead of 6+6+6+6+6). Don't remember if even finished a routine, though.
(yeah, I'm talking about integer multiplications. Floating point could be a mess, and would definitely be slow.)

Not sure if there's a simple way to do division, aside from a subtraction loop (would probably have to settle for an integer and remainder result).

There are several methods for doing this, but all are based on the division principles for multi-digit
numbers that you learned in grade school. Line up the divisor under the left-most set of digits of the dividend,
appending an imaginary set of zeroes out to the right, and subtract as many times as possible. Record the
number of successful subtractions; then shift the divisor right one place and continue until the divisor is flush
right with the dividend, and no more subtractions are possible. Any non-subtractable value remaining is called
the remainder.