Anyone can attend meetings of the after-school math club.
After school is actually quite tricky re who can and can't attend. To attend after school, you usually (most schools) have to have alternate transportation home after the club ends. If you're participating in a school team sport, those practices (here) often take place *every* day after school. If you have other types of lessons or siblings and a crazy family schedule, your parents might not be able to fit in one more after-school-day-per-week activity. If you are attending a before school activity, you simply might be tired by the end of the day.
It's not possible to find a time and method of selection that will work for everyone, and it's not easy to find a best-fit for things like this. OTOH, it's very easy to look in from the outside and say "Oh, only rottweilers who wear purple head bands are attending this activity, therefore they must be the best candidates."... without taking into account that it's quite likely that there is some other selection factor influencing who attends that may, in fact, be entirely unrelated to who is naturally a best fit for a competition or who is naturally most interested in the subject.
polarbear
ps - I'll offer up one situation that happened in my family. One of my dds was very interested in joining our school's chess club, so she went to the first meeting and stuck it out for another 1 or 2 meetings after school. She quit - not because the chess was difficult (she was, in fact, having a lot of fun with the chess) - she quit because she had a difficult time with the approach of the teacher sponsoring the club, and also because there were quite a few students in the club she didn't really feel like hanging out with. I don't think the quitting due to not enjoying the sponsor fit or not feeling like hanging out with the other kids is exclusive to a "girl's" personality either - same thing has happened with my ds and other boys I know.
