How to answer "What science or math related activities did you participate in" when I didn't?

One of the three big questions on the UW engineering application is this:
List participation in activities such as Math, Science and Engineering Talent Search or Competitions; Science or Creativity competitions; or Science Fair Projects. Please include only high school experiences.
They have a 300 word limit, and I don’t really want to leave it blank. This is my top choice school and the only way I’ll be able to afford it is with scholarships like this. The thing is, I spent so much of my high school focusing on schoolwork and band (which I thought would by typical of most engineers… not much social life haha) so I have nothing to say for this. Should I leave it blank, or should I write about how ‘my other focuses took up too much time but I’d like to make more time for that kind of stuff in college’?
Any other suggestions on how to answer it? I guess I’m overthinking it but it’s a big deal to me

Find the scientific component of something you DID participate in. There is science in band and sports without being on the science team. If you’re interested in engineering, you’d be expected to show something related to science to help them understand WHY?

Man, that’s good. The way the question is worded, though, really seems to want it narrowed to specifically science and math activities. I’ll see what I can do though.