Formulas can be written in different ways on Excel. They can be created using constants and calculation operators or by use of cell references and names. A formula can also be created using a function, a nested function, or an array formula that calculates a single result or multiple results.
To use constants and calculation operators, click on the cell to hold the formula, and type the equal sign. To enter the formula, enter the constants and operators to be used, or click the cell with a value to be used, type the operator and click another cell with a value. Press Enter. To use cell references and names, click the cell to hold the formula, and type the equal sign in the formula bar. To create a reference, select a cell or cells through semi-selection, and drag the border to expand the selection.
Ensure the cell references are color coded with square corners. Press F3 to enter a reference to the named range, select the name in the Paste name box, and click OK. Press Enter. To write a formula using a function, click on a cell, click Insert Function on the Formula Bar and select a function to use by either searching for a function or selecting from the category box. Enter the arguments by clicking Collapse Dialog, selecting cells on the work sheet and then pressing Expand Dialog.
Using nested function involves using the Function Wizard whereby it can nest up to 64 levels of functions. To write an array formula that calculates multiple results, select a range of cells to enter the array formula, and use built-in excel functions. Press "CTRL+SHIFT+ENTER" to automatically insert the formula between a pair of opening and closing braces.