Thanks. I usually admit who I am, but my original post was from a computer at my school, and I cleverly forgot my password.

While I won't be there next year -- I started about a month into the school year, wrong-footed a couple of times and never was able to recover, so I thought leaving was a wise choice -- I do want to help the faculty with their planning for a STEM curriculum next year. I think some computer programming would be a good addition: it teaches a lot of useful problem solving skills. I am looking at Scratch, Blockly, and NetLogo. I won't be in on the implementation, but the two constraints are a) chromebooks (no java) and b) no budge. I asked here because there are a lot of very knowledgeable people here.

I'll take a look at Hackerrank.