Teaching kids real math with computers/calculators

[grsbanks]

Maybe you want to invest in something that's built like tank and will be able to withstand a certain amount of bashing about. Combine that with some education relevant to the value of items as suggested by Maximilian Hohmann, then go and get a machine that's worth a bit more than your average cheapo Casio such as a DM15L. It's durable and feature-wise is ticks most of the boxes you enumerated in your last post.

If the alpha in/out is vital then go for a DM41L.

Disclaimer: I am involved with Swiss Micros but not financially. I do not stand to gain anything by recommending their machines.