Base sixty is kind of tricky. A traffic warden used a calculator to tell when the parking a driver had paid for would expire, got the wrong answer, and gave him a ticket. He got the wrong answer because he was treating time as a decimal -- so 2:49 became 2.49 -- and as you know, there are sixty minutes in an hour, not one hundred. The driver had paid for 75 minutes, so the warden found 2.49 + .75 = 3.24 and decided he had paid until 3.24. (I shudder to think what would have happened if the warden had noticed that 75 minutes is one hour fifteen minutes, and done the computation 2.49 + 1.15 = 3.64 -- obviously the time 3:64 doesn't exist.)
Have there been cheap calculators that work in hours and minutes? I feel like there would be a demand for that; calculations involving time are probably among the most common ones in ordinary life. Then again, most people seem able to do them; this sounds like an isolated incident.
(via Eric Berlin.)