Example 6-7. Relative References
For example, if =A1 is the formula entered into cell B2, cell
B2 will displat the data in cell A1, which is one row up and
one column left. Then, if you copy the contents of B2 to cell
F6, cell F6 will contain the value from E5, which is also one
row up and one column left.
For the copied cell to still refer to A1, specify absolute
references using the $ character: $A$1 refers to cell A1, no
matter where it is copied.