Worked at a retail liquor store chain for 16 years. I'm old school and the only one who never punched in 'amount tendered' on the register. If someone handed me a twenty for a $16.75 sale, I always added back up, giving them a quarter and saying that makes 17, then handing them 3 ones and saying, and 3 makes 20. I was the fastest register guy there, because if you hit cash tendered, you're going through 2 extra steps to make change. My money always came out right at the end of the shift (probably cause I wasn't a thief and if you hit cash tendered for $20 and the customer had only given you $10, you were $10 short. Funniest thing was that there was another manager there besides me (an old country gal)--when you pulled the pop-machine money, you had to extract the 5% sales tax before you rang up the money to account for the sales tax. She always multiplied the total by .95238(cause that was how the owner taught her how to do it), and was always a few pennies off. I told her all you need to do is divide the total by 1.05, and it will be exact every time--finally figured out she had never learned how to to division in school!