Finding the value of Mouse position?

When doing this math.ceil(Mouse.hit.p) it comes up wrong how do you find the value of the mouse position and says bad argument #1 to 'ceil' (number expected, got Vector3)

The Problem is your trying to do math on a Vector3 value, which isn't possible, this question's answer in the link below will help you, https://scriptinghelpers.org/questions/2171/how-can-i-round-a-vector3-to-the-nearest-stud