2. Descriptive names


It is true the cells already have names; for examples the cell A1 (relative reference) or $A$1 (absolute reference). When we use relative reference in formula and Fill Down (or Copy and Paste in another cell), the reference changes accordingly, whereas the absolute reference does not change. Sometimes it is desirable to assign a descriptive name as the absolute reference.

You must have noticed in the previous screen that when you enter the formula '=2*pi' in the cell E4, it returns the error message '#NAME?'. This is because that the name 'pi' refer to a descriptive absolute reference that is not yet defined, it is supposed to be referring to the cell E3.

To define name: Click on the cell E3 ----> Go to the 'name box' cell which is on the top left corner displaying the text "E3"-----> click on the 'name box' and type in 'pi' in place of E3, and when you press the 'enter' key, the value in the cell E4 will get changed to the right value of 2p. Continue naming the cells E4, E5 and C8 to be 'k', 'A' and delta_x respectively.