In high school, my algrebra and physics teacher had 2 TRS-80 computers (I believe they were Model I's). He would let us play on them after we did our homework or after tests. I remember typing in programs from a book of Basic and playing ASCII games and hoping, praying, that the cassette recorder would work right so we didn't have to retype it. Horrible code -- we had to debug and try to find the errors in almost every program.
Later in high school, we got a grant for 10 brand new IBM PC's. Same guy, Mr. Judd, taught a class on these that consisted of a list of problems that we had to solve on the computer. There was no book because this was in the early 80's. There was no "right" answer so it allowed us to be innovative in our approach. I probably owe my career to that hard-working, under-paid teacher for not just showing us, but allowing us to explore.