Is there a way to send or 'gift' a person Google play credits? We would like to allow students to redeem points they earn for good grades, etc for Google play credits.
From the Google Play Help pages:
You can only purchase Google Play credit to add to your own Google Play balance. At this time, aside from giving someone a physical Google Play gift card, it is not possible to add credit to another user's Google Play balance as a gift.
That said, there are places like PCGameSupply.com that allow you to buy "digital" gift cards (Google Play included)- which means the redemption codes are emailed to you rather than a physical card in the mail/store. Just pick "Send as Gift" at checkout. These always seem to come with a caveat though- digital gift cards have an activation fee on top of the face value. Personally whenever I've bought a physical gift card in a store, there wasn't an activation fee.
Alternatively, since I don't know how your points/points redemption system works, you could just buy a stack of physical $10 Google Play gift cards, and once a student has earned enough points to redeem $10 worth, give them one of the gift cards. The cards don't expire, so no need to worry about that.