This is said to be a controversial topic among educators, particularly math teachers.  I feel that all students should have the use of a calculator.  Years ago I had a student who was said to be unable to learn math.  I gave her a calculator (since she couldn't remember her operation facts) and went on to teach her how to do geometry and equations.  She could understand concepts exceptionally well, and got an A on the final in pre-algebra in 7th grade.  She had changed to loving math, instead of hating it.  So - I beg other educators - please allow students to use calculators so that they don't lose the forest for the trees, and they can see the beauty of the math concepts.