Unity UI GridLayoutGroup mousePosition over which element?

Hi there,

I have a GridlayoutGroup with 10x10 = 100 elements, and i want to know on which element my mouse clicked.

One bad way to do is by turning those 100 elements as buttons, which i want to avoid.

Right way to do is, get mouse position, then convert that position to GridLayoutGroup's Child's anchoredPosition's equalvant. and round that value to that cell.
Problem is i know the theory but not the math and how do i convert these.

So here for assistance from community.
Thanks