My wife, who is a chemist and understands fully all numerical matters,
is annoyed by the fact that I still tip 10%-rounded-up at restaurants
even though prices have gone up. I will continue to do so, especially
as long as the restaurants insist on computing the tax on the meal at
7% *before* deducting any half-off coupons I might have. When I
complain they just say "that's the way we do it".
I'm 61 years old. I can testify with certainty that numerical skills
among grade school graduates have atrophied considerably since my own
youth. When I protest students' reaching for calculators to reckon
10% of 215 they think I'm an old fuddy-duddy. I even saw the same
attitude expressed by one of the contributors here yesterday.