KISS. Teacher, Whiteboard, and a textbook. (Preferable one the student can keep at home and one in the classroom) EdTech resources are amazing for self-study, but should be divorced from the school system. There will be non-profit (Khan Academy) and for-profit options available for students and parents.
Though I am in favor of any suggestion that makes a teacher’s life easier.
However, I do have the controversial opinion that there should be no calculators allowed at all in K-12. So, I have some anti-tech bias.