Robin2:
If you can organize the maths so that divisions can be by values which are a power of 2 (e.g. 2, 4. 8. 16 etc) you can use the right shift instruction. For example >> 6 shifts the value to the right by 6 places which is equivalent to dividing by 64 (26 = 64) and that instruction is very fast.
I hope you don't mind helping a little more? My deltaTime value with the background showing is 12 milliseconds which is 1100 in binary. Shifting to the right by 3 places gives a value of 1 for my rate of movement. However when I don't draw the background, deltaTime goes down to 2 milliseconds, which is just 10 in binary, and this gives 0 when shifting right by 3 places. What do I do in this case?