In an excel spreadsheet, many people get tired of having to calculate the costs of items to get an average. Instead of inputting everything, the person can type in a formula for a range of cells and have the computer program calculate the amount for each cell.
If you want to get the average of the cells for A1 through A5, you can put it into a formula. For instance, if A1 is 90, A2 is 85, A3 is 80, A4 is 75 and A5 is 75, then you would type into the cell an equal sign and the word average.
Then you need to put in the cells, so you would type A1 colon and then A5 to show that you want the average of these cells together.