Sorry for the tardy response.
Giving you my recommendation isn't as easy as it might seem. :/
I believe Adobe stopped supporting Flash on mobile devices some time ago. While some existing presentation materials might still be Flash based, no school should be teaching kids how to program Flash for mobile devices. (In my opinion, they shouldn't be teaching Flash period....but that's just me.) I don't know if any device guarantees Flash compatibility anymore.
I'm pretty sure you can use Google Docs through just about any web browser if you can't get the Google Docs app installed formally on the device. Not sure if the Amazon store has a Google Docs app. But I think there are many how-to's on the web about getting Google Docs on Fire tablets through side-loading or rooting.
I have had excellent experience with two Samsung Galaxy Tab 2 (7in) tablets, a 1st gen Nabi, Nabi2 and a Nabi DreamTab, a Samsung Galaxy Tab 4 (10in) and an LG GTab with 4G (8in). I wouldn't hesitate to endorse any of these. I had a HiSense 10in tablet about two years ago and it was...ok, until I dropped it.