So, the question is not "What time is it?" or "What is the answer?", but "what do you think?"/"What is your opinion?", and one way we say this (about calculations, etc) is "What do you make it?" eg:
"32+49+11 = 92, I think. What do you make it?"
Obviously, we can't make something be what it is not; but it's what we say.
A relation question is "What do you make of it?" This has a different application. It means "What are your conclusions/opinions concerning it (whatever 'it' may be).
"I didn't understand that movie at all! What did you make of it?"