I was on a tram in Hiroshima today. It was a fairly full tram, and just by where I was standing, there was a family: mother, father, and son.

The son was studying math, by the look of it for junior high school entrance exams. Why you would do that on a tram is anyone’s guess, but that’s what he was doing.

Now when Japanese children do maths, they quite often write the math with their finger in the air. Actually, they do that when they’re writing Japanese characters (and practicing English, for that matter) as well.

But what was really quite cute about the situation on the tram was that the young boy was using his father’s back as a sort of slate, or whatever you want to call it, on which to write the equations he was trying to solve.

And the father? Well, he was just taking it all in his stride.