My method has always been to get my balance when I deposit money and then simply remember my total. After that when I make any purchase I just take the recipt and do a quick subtraction right on it, remember that number, and toss the recipt. It's worked out for me pretty well but I've never had much use for a register anyway. The only time I've had an overdraft problem was with when I was trying to deposit to a WA account while I was here in MA. It should take 2-3 days to clear yet the atm claimed that the cash was available, not true at all, not true to the tune of $20 charges.