Actually because there's no calculator the gen chem calculations are very simple. We should be thankful there is no calculator just for this reason.
For example, there could be a calculation involving 54g of H20 which you know equals 3 moles. I haven't seen any questions that weren't calculation equaling whole number of moles or half moles. I once saw a calculation equaling 0.25 moles but that's it.
Since the calculations are very simple round numbers, you can do most in your head.