Question

What does 3/4 on top number line represent?

Answer 1

What do you mean by "top number line?" This is not at all clear.

If by "top number line" you mean the y-axis, then "3/4" would represent the y value of the function you're graphing.

If this doesn't answer your question, please rewrite the question so that it's clearer what you want to know.

Answer 2

I think it means that it is 3/4 of a hole number or to the next lets say inches you have 1/4 more of a number to get to the next inch. Sorry if this is not what you wanted your instructions weren't clear.