The purchase of school supplies depends on what courses the student is enrolled in. It is a good idea to wait until the teacher advises you on the first few days of school exactly what is necessary for that particular course.
Required Calculator purchase:
For Math 10C, and following through to Math 20-1/20-2, Math 30-1/30-2, we recommend: TI-83 Plus, TI-84 Plus, TI-84 Plus Silver, or TI-84 Plus Pocket SE , TI-84 Plus CE
For Math 10-3, 20-3 and 30-3, a regular scientific calculator is needed.