It actually doesn't matter whether you do the division or multiplication first, but it's easier to keep track if you work left to right.
It can matter whather you do the multiply or divide first.
(12 / 3) * 2 will give a different answer to 12 / (3*2)
I'd expect " 12 / 3 * 2" to evaluate left to right, but as I said, I'd always prefer to make it obvious with brackets.