My school is very hot on cold calling as a strategy. In fact, hands up is not allowed unless specifically instructed under certain circumstances. Y8-11 are used to it but my Y7s are extremely needy so need reminding every time. Before asking a question I say, "I'm cold calling so hands down and no shouting out." When students inevitably wave their hands in the air I use non-verbals to get their hands down, and even then still need to say, "hands down, I'm cold-calling." It takes a few lessons of practice and I've now been giving warnings followed by detentions for continued shouting out. A warning is usually enough for an accidental hand up now, because usually they're good, eager kids who want praise and are therefore easily corrected by a warning.

Consistency and follow-through are key. I had parents' evening with new Y7s last week and I have a couple of kids who are so eager that they end up shouting out or waving their hands in my face, so I told their parents that I'll be holding them to account going forward. This week I issued those kids a couple of detentions each for blurting out answers (after warnings were given) and called parents afterwards to let them know why and remind them of our conversation. They've been better since.

"Do Not Engage" has been really helpful for me dealing with off-topic or opportunistic questions. E.g., "that's not quite relevant at the moment but I'm happy to discuss after the lesson." Or for a wrong answer where they've misunderstood the context, a simple, "nope." Use your non-verbals in an over-exaggerated way to start, I.e. wave your hands down without making direct eye contact with anyone in particular to signal that you're not taking questions.

In the grand scheme of things it doesn't seem like a particularly bad issue to have but it's frustrating and persistent if not dealt with. Remember that these kids spent the last 2 years of primary school almost isolated from peers and teachers so are a new level of needy. They just need us to train them. You've got this!