Student is very behind on her Math, please help.

This last September I started giving tutoring lessons to middle schoolers as a way of making some money. I'm an engineering undergrad so I'm teaching Math and Physics.

I recently got this student, she's a 9th grader, that knows almost nothing about Math, she even has trouble doing basic operations like addition and subtraction when she should be learning inequations and probabilities.

I'm a bit lost in here, I want to teach her the basic concepts but I don't know where to start and what to follow. It would be very helpful if some of you could advise on how to teach her the basics.