As a civil engineering student in Applied Mathematics in Grade 2, I can help any high school student in mathematics (taking a 2 to 8 hour math / week course) or physics (mechanics and electricity) as part of a specific course. It is a question first of all to point out the present gaps and then to take stock of the theory. Once the concepts are reviewed, a series of exercises is usually proposed to apply the material and check if it is well acquired.