How to return the position of a cell in a range

I would like to return the row of a cell in a range. For an example, I have a range of 7 cells. I want to have a function that I put in each cell in that range and it returns the order of the cells in that range, 1,2,3,4,5,6,7.

Specifically, I am trying to put in a column with an even interval of pi. For the 7 example, the first needs to be 0, then pi/6, then 2pi/6, 3pi/6, 4pi/6, 5pi/6, 6pi/6. I am using count(range)-1 to get the denominator, but would like a way to find the position of the cell in the range for the nominator. I have many ranges I want to do this for, so I am trying to avoid manually typing the positions.