How to move formula from cell to cell

I have a formula in cell B8 “=((A2*B2)+(A3*B3)+(A4*B4)+(A5*B5)+(A6*B6))” that I would like to copy that formula to other cells (C8,D8,E8…) without changing the cell reference of A2 to A6. Is there a way to do this?

I am enclosing a copy of the spreadsheet.

Current Shares Value.ods

Try

=SUMPRODUCT($A$2:$A$6;B2:B6)

Yes, it works. I just don’t see how, does “=SUMPRODUCT” simply adds the value? Could you show me how it works? Thanks for making it shorter.

SUMPRODUCT: Multiplies corresponding elements in the given arrays, and returns the sum of those products. (There - by link - is an example with a picture)

I think the attachment may be what you want using absolute references for the column A - shares.ods.

Thank you for the suggestion, it works fine now.