 And when they hand you your change and be able to do it in your head, not necessarily super fast, but you should be able to look at the change that they hand you and know whether or not they gave you the right amount of change. Like if you pay for something with a 20 and it's $10.37, so that's going to be like $8.63 that you get back. And so you should be able to kind of do the math, know what you're supposed to get back, and then when they hand you the coins, be able to kind of add that up so you know that you got the right amount back.