I agree, in part. Students should be given tools only after they have been taught, and mastered, the underlying principals behind the tool. I don't understand why you would prohibit a student from using a tool, like a calculator once they understand basic math. For example, if an assignment or test calls for the student to average a list of number (as part of a larger operation). Why not permit them to use a calculator for that? Sure you could make them do the math on paper, but that can be slow, tedious, and introduce errors that further complicate the lesson. Consider that if they use a calculator, they can practice more problems in a shorter period of time, thus helping them to learn and understand the larger lesson.