So you've never had an encounter at a bar, moderately intoxicated, where you regrettably put the server on the spot by not understanding why you are supposed to

So you've never had an encounter at a bar, moderately intoxicated, where you regrettably put the server on the spot by not understanding why you are supposed to pay the amount they're telling you you're supposed to pay? Cause I have, and I have doubts it was significantly more complicated math than basic integer addition and subtraction. I also do use a calculator even for basic, low value, integer math, because what do you know, in my perfectness I often had an issue with numbers not ending up as what they were supposed to. There's also the quite accessible and extensive history of human calculators and the extensive error correction strategies they had to employ because they'd keep cocking up calculations. Come on...