Do you have recommendations on how many AP courses a student should have at the time of applying to college?
The expectations at the most selective colleges in the country are that the student will go to the highest level available in all five major subjects (math, science, history/social science, English and foreign language). This can and often does mean going to the Advanced Placement level in all five subjects by the time the student is a senior, though not all high schools will offer AP level courses in all subject areas. If they are not offered, the student will not be penalized during the college admissions process for not taking them (you can’t take what isn’t available!). Those colleges also expect to see excellent performance in those courses, ideally As in everything taken in high school.