I would often do this in class (or at work, in meetings) either because I really didn't understand, or because I could tell a bunch of others didn't. But it is

I would often do this in class (or at work, in meetings) either because I really didn't understand, or because I could tell a bunch of others didn't. But it is fine to phrase it something not being clear, asking if they can try to explain a different way to make it more clear, or trying to rephrase whatever it is myself.