A constant is an entry that does not change. It may be a number such as a student's test score or something descriptive like a label. A formula is a combination of numeric constants, cell references, arithmetic operators, and/or functions that displays the results of the calculation. Every cell contains either a constant or formula.

A formula always begins with an = sign. Symbols such as +, -, and / indicate addition, subtraction, multiplication and division. Any expression that is in parenthesis are evaluated first, followed by multiplication or division from left to right, then finally addition or subtraction from left to right. An example of a formula would look like this =(B3+C3+2*D3)/4.

In the example below, formulas for calculating the total scores of each student and the overall class averages can be seen.