Our school district's BYOD (bring your own device) policy starts in 5th grade. Every student carries their own chromebook.
This is very important! Parents should always add their google account *before* a student adds their account. See the ProtectYoungEyes' Chromebook setup instructions (layer 3 instructions).
Controls are useful in conjunction with behavior management. See Parenting Tips.
One of the most insightful comments about screens and children is: Once they have a browser and an online presence, that will become the focus of their world, not your family. While children and adolescents learn very fast, they struggle making good decisions. If you think there are things you still want to teach your children, to connect with them about, then you, as parent, will take this statement seriously. Good family agreements can guard against a wholesale “giving over to the world” while allowing a teenager to (slowly) become part of that world.
There is no one-size fits all contract - be prepared to either pick one that is only "okay" or to take time to craft one that fits your family values. Revise it over time.
The school district has recommended the low cost Acer Chromebook CB3-131-C3SZ and ASUS Chromebook C202SA-YS02 in the past. Here is some more information to think about. (Last updated June 2019.)
Significant discounts are available on prime day (usually July 16th) and after Thanksgiving. Frequently refurbished units are available at a discount.
These will work fine for any student. No touch screen means they're easier to repair.
A Chromebook that uses USB-C to charge means extra chargers are easier. Some Chromebooks can also run android apps (usually intentionally disabled in school accounts) and some can run linux apps. Both android and linux capabilities can cause more distractions but they do make the Chromebook more future proof.
Theoretically a ruggedized Chromebook can take more of a beating.