How long will devices last? Will we have to purchase a new device every 3 years?

Some devices will last longer than others. If you purchase a original iPad 1 for $79 on eBay, it might only last a year. If you spent $2,579 for a top of the line Mac Book Pro it will probably still be useful for a student six or more years later (not that we're recommending you do that). 

We expect that any of the devices in the List of Recommended Devices will still work for the things that a student needs to do for at least 3 years. More expensive devices tend to last longer, but recognize that that is a generalization.

Portable computing devices are changing rapidly, but we do not anticipate changing our minimum requirements every year and we recognize that if you purchase a device that meets those requirements it would be unreasonable for us to expect you to upgrade within a few years. Depending a little on what type of device you buy we thing you might buy a device in 6th grade and another sometime between 9th and 11th grade.