All of my kids knew that my wife and I would actively involved in their education and would be keeping close tabs on their grades. In the case of our son,when he began having problems with high school math, we reacted immediately. Through talking to him and his teacher we worked to figure out the underlying issue(s), helped him work through his homework, and got him outside tutoring or those things that just weren’t clicking. We also limited TV, non-school computer use and phone time until schoolwork was done. We made it clear that school was “job” and he was expected to take it seriously as such. It wasn’t easy for him or for us, but it worked because we started early and stayed involved. Not intervening until half way through the semester, while not impossible to overcome,makes the chances of success much lower. My son will never be a math enthusiast, by any stretch, but he passed the classes and graduated on time without summer school.
Of course, all of the above goes out the window if it is truly a lack of ability. That wasn’t the case with my son, it was more A) lack of interest, B)it didn’t come easy like he was used to with everything else, C) had little perceived value for one who aspired to be a musician and D) being a teenage boy. That’s why rooting out the base issues is the critical first step - it sets the agenda for all actions to follow.