1 iPad-per-student programs make no sense. An iPad gets software updates up to 4 years and then becomes a paperweight, however during that last 1-2 years, it's so freaking slow, kids are waiting for the tablet to do something. At the very least while tablet SoCs are still exponentially increasing in performance, it's a terrible time to buy (much like computers in the 90's that really did need replacing every few years).
The most I would recommend is giving a teacher an iPad, having an Apple TV in the classroom hooked up to a TV, and apps that improve learning of concepts through interactivity far better than pen and paper ever could. Keeps costs very low, doesn't give students iPads to distract themselves with, and even if they need to be replaced every few years, it's not a criminal use of the limited funds a school has.