When splitting accounts to put into the register and using the calculator to break down the totals, I also want to add the sales tax to the amount. It can be more difficult than it should be to use the calculator to do this. It would be great if we could input a set tax amount into the program for purchases for the area we live in, so that when a split amount is figured, we can simply hit a button that will add the calculated tax to that amount if needed.