How to add an integer to the result of SELECT COUNT()

I thought this would be a slam-dunk, but apparently not. I have a SELECT COUNT(id) FROM {table X}, which functions properly.

I then want to divide the results of that COUNT() by the results of another SELECT COUNT() using the “/” operator, but I get a syntax error on that “/”

The exact expression I’m trying to evaluate is below. I want to divide the number of id values in the members table by the number of id values in the orchestras table. The individual SELECT statements function properly, but the “/” is apparently a problem, and I can’t determine why.

Has anyone seen something like this, and/or does someone have any ideas about what to try? I’m really at the end of my proverbial rope.

SELECT COUNT(id) FROM members / SELECT COUNT(id) FROM orchestras