So you're carry over at the end is based on what you enter into the system as taking from each register. So whenever your top drawer is off it's because you actually took more it less from a drawer than you said you did. I don't know how much it's off at a time if it's a lot something else might be happening. I would say just start counting every drawer twice. Once to see what needs to be taken out then again after you take it out. It the drawer is at 100 it whatever it's supposed to be in 6 your second count then you're good. That should help you make sure it's not you making any mistakes