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Lesson 10: Working with Basic Functions


Working with basic functions

Lesson 17

Figuring out formulas for calculations you want to make in Excel can be tedious and complicated. Fortunately, Excel has an entire library of functions—or predefined formulas—you can take advantage of. You may be familiar with common functions like sum, average, product, and count, but there are hundreds of functions in Excel, even for things like formatting text, referencing cells, calculating financial rates, and analyzing statistics.

In this lesson, you'll learn the basics of inserting common functions into your worksheet by utilizing the AutoSum and Insert Functions commands. You will also become familiar with how to search and find various functions, including exploring Excel's Functions Library.

Basic functions

A function is a predefined formula that performs calculations using specific values in a particular order. One of the key benefits of functions is that they can save you time because you do not have to write the formula yourself. Excel has hundreds of functions to assist with your calculations.

To use these functions correctly, you need to understand the different parts of a function and how to create arguments in functions to calculate values and cell references.

You can download this example for extra practice.

The parts of a function

The order in which you insert a function is important. Each function has a specific order—called syntax—which must be followed in order for the function to work correctly. The basic syntax to create a formula with a function is to insert an equals sign (=), function name (SUM, for example, is the function name for addition), and argument. Arguments contain the information you want the formula to calculate, such as a range of cell references.

Syntax of a basic functionSyntax of a basic function

Working with arguments

Arguments must be enclosed in parentheses. Individual values or cell references inside the parentheses are separated by either colons or commas.

  • Colons create a reference to a range of cells.

    For example, =AVERAGE(E19:E23) would calculate the average of the cell range E19 through E23.
  • Commas separate individual values, cell references, and cell ranges in parentheses. If there is more than one argument, you must separate each argument by a comma.

    For example, =COUNT(C6:C14,C19:C23,C28) will count all the cells in the three arguments that are included in parentheses.

To create a basic function in Excel:

  1. Select the cell where the answer will appear (F15, for example).
  2. Type the equals sign (=), then enter the function name (SUM, for example).
    Creating a SUM functionCreating a SUM function
  3. Enter the cells for the argument inside the parentheses.
    Adding cells to the function argumentAdding cells to the function argument
  4. Press Enter, and the result will appear.

Excel will not always tell you if your function contains an error, so it's up to you to check all of your functions. To learn how to do this, read the Double-Check Your Formulas lesson from our Excel Formulas tutorial.

Using AutoSum to select common functions

The AutoSum command allows you to automatically return the results for a range of cells for common functions like SUM and AVERAGE.

  1. Select the cell where the answer will appear (E24, for example).
  2. Click the Home tab.
  3. In the Editing group, click the AutoSum drop-down arrow and select the function you want (Average, for example).
    AutoSum commandAutoSum command
  4. A formula will appear in E24, the selected cell. If logically placed, AutoSum will select your cells for you. Otherwise, you will need to click the cells to choose the argument you want.
    AutoSum selects and dsiplays cell rangeAutoSum selects and displays cell range
  5. Press Enter, and the result will appear.

The AutoSum command can also be accessed from the Formulas tab.

You can also use the Alt+= keyboard shortcut instead of the AutoSum command. To use this shortcut, hold down the Alt key and then press the equals sign.

Watch the video below to see this shortcut in action.

The Function Library

There are hundreds of functions in Excel, but only some will be useful for the type of data you're working with. There is no need to learn every single function, but you may want to explore some of the different types to get ideas about which ones might be helpful to you as you create new spreadsheets.

A great place to explore functions is in the Function Library on the Formulas tab. Here, you can search and select Excel functions based on categories such as Financial, Logical, Text, and Date & Time. Click the buttons in the interactive below to learn more.

labeled graphic

Date & Time

The Date & Time category contains functions for working with dates and time and will return results like the current date and time (NOW) or the seconds (SECOND).


The AutoSum command allows you to automatically return results for common functions.

Recently Used

Use the Recently Used command to access functions you have recently worked with.


The Financial category contains functions for financial calculations like determining a payment (PMT) or interest rate for a loan (RATE).

More Functions

More Functions contains additional functions under categories for Statistical, Engineering, Cube, Information, and Compatibility.

Math & Trig

The Math & Trig category includes functions for numerical arguments. For example, you can round values (ROUND), find the value of Pi (PI), multiply (PRODUCT), and subtotal (SUBTOTAL).

Lookup & Reference

The Lookup & Reference category contains functions that will return results for finding and referencing. For example, you can add a hyperlink (HYPERLINK) to a cell or return the value of a particular row and column intersection (INDEX).


The Text category contains functions that work with the text in arguments using tasks like converting text to lowercase (LOWER) or replacing text (REPLACE).


Functions in the Logical category check arguments for a value or condition. For example, if an order is more than $50 add $4.99 for shipping, but if it is more than $100 do not charge for shipping (IF).

Insert Function

The Insert Function command allows you to easily search for a command by entering a description of what you are looking for.

To insert a function from the Function Library:

  1. Select the cell where the answer will appear (I6, for example).
  2. Click the Formulas tab.
  3. From the Function Library group, select the function category you want. In this example, we'll choose Date & Time.
  4. Select the desired function from the Date & Time drop-down menu. We'll choose the NETWORKDAYS function to count the days between the order date and receive date in our worksheet.
    Function Library Date & Time category Function Library Date & Time category
  5. The Function Arguments dialog box will appear. Insert the cursor in the first field, then enter or select the cell(s) you want (G6, for example).
    Selecting cell for the Start-date fieldSelecting cell for the Start_date field
  6. Insert the cursor in the next field, then enter or select the cell(s) you want (H6, for example).
    Selecting cell for the End_date fieldSelecting cell for the End_date field
  7. Click OK, and the result will appear. Our results show that it took five days to receive the order.

The Insert Function command

The Insert Function command is convenient because it allows you to search for a function by typing a description of what you're looking for or by selecting a category to peruse. The Insert Function command can also be used to easily enter or select more than one argument for a function.

Using the Insert Function command

In this example, we want to find a function that will count the total number of supplies listed in the Office Supply Order Log. The basic COUNT function only counts cells with numbers; we want to count the cells in the Office Supply column, which uses text. Therefore, we'll need to find a formula that counts cells with text.

  1. Select the cell where the answer will appear (A27, for example).
  2. Click the Formulas tab, then select the Insert Function command.
    Insert Function commandInsert Function command
  3. The Insert Function dialog box will appear.
  4. Type a description of the function you are searching for, then click Go (Count cells with text, for example). You can also search by selecting a category.
    Searching for a functionSearching for a function
  5. Review the results to find the function you want (COUNTA, for example). Click OK.
    Reviewing function search resultsReviewing function search results
  6. The Function Arguments dialog box will appear. Insert the cursor in the first field, then enter or select the cell(s) you want (A6:A14, for example).
    Selecting cell range for Value1 fieldSelecting cell range for Value1 field
  7. Insert the cursor in the next field, then enter or select the cell(s) you want (A19:A23, for example). You can continue to add additional arguments if needed.
    Selecting cell range for Value2 fieldSelecting cell range for Value2 field
  8. Click OK, and the result will appear. Our results show that 14 Total Supplies were ordered from our log.

If you're comfortable with basic functions, you may want to try a more advanced one like VLOOKUP. You can check out our article on How to Use Excel's VLOOKUP Function for more information. If you want to learn even more about functions, check out our Excel Formulas tutorial.


  1. Open an existing Excel 2010 workbook. If you want, you can use this example.
  2. Create a function that contains more than one argument.
  3. Use AutoSum to insert a function. If you are using the example, insert the MAX function in cell E15 to find the highest-priced supply.
  4. Insert a function from the Functions Library. If you are using the example, find the PRODUCT function (multiply) to calculate the Unit Quantity times the Unit Price in cells F19 through F23.
  5. Use the Insert Function command to search and explore functions.