The rounding up of the total for a pretty number is where I draw the line, math-wise. I’m barely able to do the other math 🤣

In your $13.57 scenario I would just round up to $15, divide by 5 to get $3 for a tip, and the total would be $16.57. Bam, math done.

But then again I’m also the type who doesn’t round up @ the gas pump either. Very few other transactions are round numbers so 🤷🏼‍♀️