You can quickly add worksheet numbers by building a formula that uses Excel’s SUM function. Adding a range of numbers is probably the most common worksheet calculation, so it is useful to know how to use Excel’s SUM function.
Although you can use SUM to add individual cells or a rectangular range of cells, you will most often need to add a row or a column of data. In this case, when you use the SUM function in a formula, you can specify as the function’s argument a reference to either a row or a column of numbers.
Build an AutoSum Formula:
You can reduce the time it takes to build a worksheet as well as reduce the possibility of errors by using Excel’s AutoSum feature. By default, the AutoSum tool adds a SUM function formula to a cell and automatically adds the function arguments based on the structure of the worksheet data.
However, you can also use AutoSum to quickly create simple formulas that use common functions, such as AVERAGE, COUNT, MAX, or MIN.