Everyone makes math errors. This is OK.

I was collaborating with one of the instructors here, and he let me use his existing online quizzes. The first one was a unit conversion quiz.

I went through and checked them first. The first one didn't work. Tried it several times.

So I told him. He was super apologetic, but of course I wasn't judging him, because as I said, we all make mistakes. I wanted him to know so students would get the chance to be right (the correct answer wasn't one of the choices). We worked the error out quietly.

Check each other's work - this is what happens when you work in industry (when it's done right). Figures get checked. And be open to polite correction, because sometimes, we're all wrong.

NOTE: this does NOT mean embarrass people at meetings, talk over them, etc., and be conscious of factors of race and gender and other privilege in how you come across. In this case it was two white dudes. When in doubt, make the assumption that you might be wrong.