Been a while since I was in elementary school but I don't recall calculators being banned.

realistically you can't ban computers for home work as you dont control the environment. and as for banning them for exams that may work for most of the humanities math chemistry and physic, but good luck trying to teach a computer science degree without computers, or graphic design, or any of a number of of programs that are reliant on them if you want student to be competent with standard tools of their trad which are on computers. audio engineering computer video editing computers