So I just walked down to my local dealer, oops I mean gas station, to buy a pack of smokes.
$12.20 is the total. I handed the attendant a 20 dollar bill and she keyed it in. Then I handed her a quarter.
She couldn't make change. I looked at her and said, "you owe me $8.05." She said, "thanks" and handed me my change.
Now, I know I'm a freak because I played bank as a kid, but seriously, that's simple math. One just has to count backwards. Add $0.05 equals $0.25 and $8 equals $20.
Don't get me started on actually counting back the change. I remember, way back in 1994, being complimented on my ability to count back change. At the restaurant I worked at, we were so busy that we didn't actually clear out bills. We just took the money and cleared the bills out later. We had to do the mental math. Oooh! The horror! I also walked uphill to school, barefoot...