User blog comment:BunsenH/Uncertainties/@comment-25404524-20160923025356/@comment-24577221-20160924170419

All correct except that there are 2 instances of 17 items; see above. Perhaps you were misled by the horizontal lines being in increments of 2 -- I have changed this aspect of the graph so the increments are 1.

When I was in grade 7, my science class spent an entire week of classes flipping pennies to learn about the basic stuff about the curves and probabilities, including the so-called "law of averages". After the first day, I complained to my mother about the waste of time and that I was really bored, since the results were (to me) obvious. My mother talked with the teacher; he quizzed me about all of the things that my class was to be learning on the subject, and for the rest of the week I sat in the "teacher's room" reading a late-high-school or first-year-university textbook about genetics. I suppose it was something he had sitting around, something that didn't require him to do any extra work.

The stuff about standard deviations I'm not so sure about. Possibly grade 12, probably grade 13, and definitely in first-year university. At the time, our high school went to grade 13, but now it stops at grade 12. I don't know how that affects what is taught when.