Presented below is an introduction on how to type a formula.
Formulas are the calculation backbone of Excel and knowing how to type one is essential to using Excel.
An Excel formula is what you type in a worksheet cell to perform a calculation on a Microsoft Excel worksheet. Basic Microsoft Excel formulas look like the basic math and algebra equations that you learned in grade school and high school. To begin a formula in a cell, you type an = sign followed by what you want to calculate. For example if you typed =1+3 in worksheet cell the value returned would be 4. To make the formula more powerful, you can replace the 1 and 3 with cell references like =A1+A2. When enter is pressed the formula will sum the values that are in cells A1 and A2. If either A1 or A2 is changed in value and Enter is pressed, the formula referencing those cells will recalculate automatically summing the new values. These concepts are illustrated in the graphic below.
In addition to just basic math, Excel formulas can also be used to run computer programs called Worksheet Functions. Worksheet Functions run when their name and argument list are typed in a formula and Enter is pressed. The reason why you want to learn about worksheet functions is they can perform many different types of calculations that are impossible or next to impossible to perform by using just standard formulas like the ones pictured above. An Excel formula that runs the SUM function is pictured below. The SUM function can accept a large number of values and calculate their result without having to use the + sign like in the formula above.