To create a formula, select a cell and type equals to begin. Google sheets may suggest one or more functions or ranges for the formula, based on the data and the sheet, once you begin typing. Type equals into cell C_11 to show how Google sheets suggests and appropriate Sum formula for the column. This function box will show the functions based on what has been typed, along with a brief explanation of the function's purpose. Type the open parentheses key to begin selecting a range to apply the formula too. A range can be selected by typing the beginning and ending addresses of the cells in a range, clicking and dragging to select the cells, or by using the arrow keys on the keyboard of your device. To select cells that are not adjacent for the range, hold the control key on Windows, or command key on MacOS, and select the cells for the range. As cells are selected for the range, they will be highlighted in a color that they're address appears in, as part of the formula for easy identification. The formula will also appear, and can be edited in the formula bar at the top of the sheet. Functions can also be added to the sheet, by selecting functions in the toolbar and selecting one from the menu. While Google sheets supports many different functions, there are several that are frequently used to make calculations in a spreadsheet. The simplest and possibly most utilized function is Sum. Sum returns a sum of the series of numbers and of cells. Suppose we want to see the sum of the sales for January. Select cell C11, and begin by invoking the function by typing equals sum. At the range inside parentheses, separated by a colon, (C3:C10). The resulting formula will appear as equals SUM(C3:C10). In cell C11, the total of the cells will appear. In fact, a preview of the result of the formula will appear. To apply the formula, hit Enter. Selecting that number will display the formula that produced it in the formula bar, where it can be modified. Did you notice that Google Sheets actually suggested that formula for me once I started to type into the cell I11? We could repeat the process for all other months, but we can also copy the formula across by simply dragging cell C11 across. Drag the cell C11 to the right as far as N11. Type total sales into A11, to ensure we know what the values in this row represents. Another common function is average. Average returns the numerical average value in a dataset ignoring text. Using the previous example, a formula using average would look like equals average, (C3:C10). Type average into cell O1, then add the formula AVERAGE(C3:N3) into cell O3. Note how sheets suggests the cell range. Before, we were able to drag the total for January across to populate all months, similarly, we can populate the averages. This time, we can simply double-click on the bottom right of cell O3, and this will fill down the formula for us. Sheets will automatically stop at the row where the formula is no longer relevant. Delete the contents of cell 0_11 and make row 11 and column O bold.