If you know your multiplication then you can easily do division. Here's some 2nd grade math.
If you know your times tables for 4, like 4x4 then you know 20 divided by 4. If you don't, then add on
Easy peasy 3rd grade stuff! 20 divided by 4? Just add on 4 with your fingers until you get to 20! The number on your hands is the answer!! If you have double digit division then do this
240 divided by 12. Just multiply the numbers on the tens side and then carry them to the other side, I'm not smart enough to explain the other carrying stuff.