Updating some functions manually but others automatically

[jeffcia]

I am trying to create a simple worksheet with random numbers, and I would ONLY like the worksheet to create new values when the students open the worksheet,
but I would like to tell them if they have the answer correct every time they fill in the answer.
I DO know how to create the answers, use an =if() and =randbetween().

I just need help with the updating.

TIA!