Does the school have a robotics team? If not, will other teams allow your kiddo to join their team (I know some kids who did this). Or are there teams at other lower level schools where your kiddo could mentor the younger kids? Are there any math tutoring companies in town (Mathnasium, Kumon, etc.) where they could work? Can your student start a club if there is something in particular that interests them? Like maybe start a STEM club and bring in speakers with different jobs in various STEM related fields to talk about their careers.
I know of college confidential it looks like all kids are getting this amazing research and hands on experience in high school, but honestly I don’t think that’s typical in most cases. Where we live almost no one has those types of experiences. IMO, I don’t think schools expect a high schooler to have hands on skills in Chem and Physics. Taking honors and AP classes in them shows interest. In high school kids are still trying to figure out their interests.