Is this not already common knowledge? It's taught pretty extensively in one of the required lower div CS classes at my university, and it's usually in other schools' curriculums from what I've seen.
Somewhere around half of the candidates I interview have a tough time with hexadecimal, and definitely can't do bit manipulation without help.
It's kind of depressing, but I've adjusted how I ask my problem since it's not actually needed to demonstrate the skills I want to see. It doesn't take long to learn bit manipulation when it's needed, even though it seems like a foundation of computing to me.
Learned to integrate in High School, never used it again for years.
Used in like 1 out of 5 Math classes at the start university.
Haven't needed it for a good.. 13 years I guess?
Indistinguishable from "can't really integrate shit" without some hours of relearning.