When you set up a worksheet, you should use cell references in formulas whenever possible, rather than values.

Constant

Explanation:

One of the flexibility of worksheet is using cell references to get the value of a cell, this will make the overall formula update itself when cell values are changed, but when using a constant to make computation the formula is not keeping track of the contents of the cells for any change and this will make it a fresh work to get a value based on changed values.