Everyone seems to be saying that they knew the watches answer, Clover. How come I didn't then? Perhaps it's because i HATED invigilating exams? I always wanted to shout "Boo!" as loud as I could ;-)
Only thing I could take into exams were log tables for maths and science. My brother would have suggested slide rule, but I couldn't get the hang of them.
Slide rules were essential when I took A-level Maths, TonyV (and, indeed, when I did my teacher training). I reckon I could still remember how to use one!
I bought my first calculator with my first month's pay from teaching in 1975. It cost a small fortune!
It's hard for one's brain to combine unimportant trivia (such as football) with matters of life and death significance (such as cricket) though, isn't it, Ken?