Ask HN: Donating old Android tablets to an orphanage, how to set up?

A local company went bankrupt, and through a friend, I came into possession a stash of old (but functional) Android devices. I volunteer at an orphanage, and they accepted the donation of the tablets, if it is useful to the kids in any way. The kids are of age 8+.

These devices include Galaxy Tab, Motorola Xoom, Acer iconia etc. I looked into PostmarketOS and Debian Mobile, but they're not ready for these older devices yet. Most of these tablets run Android Gingerbread. I would like if these devices can be useful for teaching maths/science/programming etc.

What could be the best way to set these old devices that could be beneficial to the kids at the orphanage? Any suggestion is highly appreciated.