Absolute References
When you
need to work with one particular cell you need an Absolute reference.
Try it:
Select cell D6. The Formula bar shows
=D5+B2.
Now, click
on B2
in the Formula bar . When you
hit the F4 function on the top row of the keyboard, the cell
reference becomes $B$2. This means go to B2 only, and no place else,
to get the data.
Select cell D6 and AutoFill the revised equation
to the rest of the rows.