Basic Math 1

Lesson 9: Basic Math Formulas & Operators

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In Lesson 9, we will explore how to perform basic math calculations in Excel using formulas and math operators. We will walk through creating simple formulas to add, subtract, multiply, and divide values in different cells, as well as how to use constants and exponents. I will show you how to enter formulas correctly, emphasizing the importance of starting with an equal sign, and demonstrate how Excel automatically updates calculations when data changes. We will also discuss how Excel displays results and formulas, and how to clear cell contents or entire columns when finished.

Navigation

Prev: Lesson 08
Next: Lesson 10

Keywords

TechHelp Excel, Excel formulas, Excel math operators, Excel addition, Excel subtraction, Excel multiplication, Excel division, Excel exponentiation, Excel formula bar, Excel cell references, Excel recalculate, Excel delete column, Excel clear contents

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Intro

Transcript

In lesson 9, we will learn how to perform calculations in Excel. We will learn how formulas work, and we will learn about the basic math operators. As we have seen in our previous lessons, Microsoft Excel is great for storing data. But what if you want to perform some calculations on that data? Being able to store all of this sales data is handy, but I want more. I want to be able to calculate a total for each month and for each sales rep.

Before we learn how to do that, let's see how basic math operations work in Excel. Let's come down here and click on Sheet 2 to move to a blank worksheet in the same workbook. This will give us a blank sheet to do some experimenting on.

Let's type in a couple of numbers. In cell A1, I will put the number 10, enter, and in cell A2, I will put the number 5, enter. Now my goal is to add these two numbers together.

In Excel, math formulas work backwards from traditional math. For example, in a normal math problem, you might see x plus y equals z. Well, in Excel, I want you to think backwards. Think z equals x plus y.

Now, instead of x and y, we are going to substitute in the cells that we want to add. So in this case, z equals A1 plus A2 if you want to add those two cells together. Now all you do in Excel is just get rid of the z. Equals A1 plus A2 is what you put into a cell. The z is the current cell that you are in. You are going to set z's value or the current cell's value equal to A1 plus A2.

It is very important in Excel to make sure that you start each formula off with an equal sign. You have to use the equal sign to indicate that you are starting a formula.

Now let's go back to our spreadsheet. Just so you can see a little better, I am going to zoom in just a little bit using the zoom tool here. Zoom in just a little bit. There we go.

Now in Excel A3, I want to put the result of adding A1 plus A2. To begin a formula, I start with the equal sign. Then you type in the two cells you want to add, so A1 plus A2. Then press Enter. There is my result: 15. Fifteen is equal to 10 plus 5.

Again, I just want to take a second to stress: do not forget the equal sign. Whenever I teach the Excel Basics class in the classroom, 90 percent of the time when a student does not get their formula right, it is because they forgot the equal sign. If you do not type the equal sign in, it is not going to work right.

One of the nice things about Excel is that Excel will automatically recalculate all of your formulas if the data changes. For example, if later on, A1 changes to 12, notice how my calculation down here updated itself. This is because A3 is equal to A1 plus A2. You can see that up here in the formula bar. Whatever A1 plus A2 happens to be, in any given moment, will show up in A3.

When it comes to working with formulas, the cell will always show the result of the formula, but the formula bar will show you what is actually in the cell, the formula itself. If you want to change the formula, you can use any of the techniques that I showed you earlier. You can double click on the cell, or you can click up here in the formula bar, or you can press F2.

I am going to click here in the formula bar. Notice A1 and A2 are different colors. You can see little colored boxes around the cells down here. That is just Excel's way of letting you see visually what cells or ranges of cells you are working with. A1 plus A2 show up in color. We will see how to work more with these colored boxes in a future lesson.

Let's say I want to change this formula. Let's say instead of addition, I want subtraction. I will click right here after the plus. I will press the backspace key, and then put a minus sign in there. Now I have equals A1 minus A2, and then I will press Enter. Now you can see the formula has changed from addition to subtraction.

Here are all of Excel's basic math operators. We have addition, the plus sign. Subtraction is the minus sign. Division is the forward slash. Multiplication is the asterisk, the little star - on most keyboards it is shift 8. Exponentiation is raising a number to a power. Like 3 to the fourth power would be 3, and then that symbol called a caret, followed by a 4.

If you want to change the formula, you can click here, click on the formula bar, or just double click on the cell. Now I will change this to A1 times A2. That is multiplication. There we go, there is a 60: 12 times 5.

When working with formulas, you are not limited to just typing in cells. You can also type in constants or numbers. For example, I could say equals A3 divided by 10. That will take the value in A3 and divide it by 10, which should give me a 6. There we go. That takes the value in cell A3 and divides it by 10. You do not always have to use a cell value in your formulas. You can use actual numbers.

Want to raise a number to a power? That is easy. Let's say you want 6 squared, so equals A4 raised to the second power. Now, notice I typed in a lowercase a there. That is fine. Excel does not care if you type in capital or lowercase letters for your cell references. A4 to the second power, 36, 6 times 6.

We are done with this temporary data. I want to delete the whole column. I could just select all of this data and press delete, or I can wipe out all of the information in the column at once by simply clicking up here on the column header, the actual letter A. That will select the entire column. Now I can press delete on the keyboard.

That is how you clear the contents or erase an entire column. Technically, it is called clearing a range of cells.

Quiz

Q1. What must all formulas in Excel begin with?
A. An equal sign
B. A plus sign
C. A dollar sign
D. A minus sign

Q2. If you want to add the values in cells A1 and A2, what formula should you enter in A3?
A. =A1*A2
B. =A1-A2
C. =A1/A2
D. =A1+A2

Q3. What happens if you change the value in a cell that is referenced by a formula?
A. Nothing happens until you press F9
B. The formula does not update automatically
C. The formula updates automatically
D. The formula is deleted

Q4. How can you edit an existing formula in a cell?
A. Double-click the cell
B. Click in the formula bar
C. Press F2
D. All of the above

Q5. Which symbol is used for multiplication in Excel formulas?
A. x
B. &
C. *
D. %

Q6. How would you divide the value in cell A3 by 10 in Excel?
A. =A3*10
B. =A3+10
C. =A3-10
D. =A3/10

Q7. What symbol is used to raise a number to a power in Excel?
A. ^
B. #
C. @
D. $

Q8. When writing cell references in Excel formulas, what does Excel think about uppercase versus lowercase letters?
A. Only uppercase letters work
B. Only lowercase letters work
C. Both uppercase and lowercase letters work
D. Letters are not used in cell references

Q9. What is displayed in a cell that contains a formula?
A. The formula itself
B. The value resulting from the formula
C. An error unless you show formulas
D. The contents of the previous cell

Q10. How can you quickly clear the contents of an entire column in Excel?
A. Click the column letter and press Delete
B. Highlight the cells and type 0
C. Use File > Clear Data
D. Right-click and select Remove Column

Answers: 1-A; 2-D; 3-C; 4-D; 5-C; 6-D; 7-A; 8-C; 9-B; 10-A

DISCLAIMER: Quiz questions are AI generated. If you find any that are wrong, don't make sense, or aren't related to the video topic at hand, then please post a comment and let me know. Thanks.

Summary

Today's video from Excel Learning Zone is all about performing calculations in Excel. In this lesson, I will show you how formulas operate and introduce the basic mathematical operators you will use in your spreadsheets. Excel is not just for storing data - it is also an excellent tool for performing calculations such as sum totals for sales reps or for monthly results.

Before we jump into applying calculations to real data, it is important to understand how basic math functions work in Excel. I recommend opening a new, blank worksheet for practice. For this example, let us enter the number 10 into cell A1 and the number 5 into cell A2. The goal here is simply to add these two values together.

Excel formulas are a bit different from what you might be used to in standard math classes. In most math problems, you might see x plus y equals z. But in Excel, I want you to think of it a little differently: z as the result cell, equals x plus y. When you type a formula, you only include what is on the right side of the equation - the current cell will always become the result.

So if you want to add A1 and A2 together, you would type an equals sign, then A1 plus A2. Do not include the variable for the result (that is handled automatically by whichever cell you are typing the formula into). Always remember to start your formula with the equals sign - that tells Excel you are entering a formula and not just text or a number. Most formula errors I see when teaching Excel basics are caused by someone forgetting that equal sign.

Now, if you enter the formula for addition in cell A3, it will look like this: equals A1 plus A2. Press enter and Excel will calculate the sum, so you will see 15 if your example numbers are 10 and 5. What is great about Excel is if you go back later and change A1 - say, update it to 12 - the result in A3 will instantly change as well since Excel recalculates formulas whenever the data changes.

If you look at the worksheet, you will notice that the cells show the result of the formula, but you can see the actual formula itself in the formula bar at the top. If you want to modify your formula, you can edit it there, double-click the cell, or press F2 to get into edit mode. Excel will also highlight each referenced cell in a different color along with matching colored outlines, so you can easily see which cells are involved in the calculation.

Let us look at some other mathematical operations. If you want to subtract instead of add, simply change the operator from the plus sign to the minus sign in your formula. The subtraction result will appear after you press enter.

The main basic math operators in Excel are: plus for addition, minus for subtraction, the forward slash for division, and the asterisk (shift 8) for multiplication. For exponentiation (raising a number to a power), you use the caret symbol. For example, raising 3 to the 4th power would involve typing 3 followed by the caret and then a 4.

You are not limited to referencing cells in your formulas; you can use constants as well. For instance, you could enter a formula that divides the value in a cell by 10 or multiplies two constants together. Excel does not care if you use uppercase or lowercase letters for cell references, so A4 and a4 are treated the same way.

Suppose you want to raise the value in cell A4 to the second power. You would use the caret operator for that, and Excel will show the result once you enter the formula.

If you want to clear out your practice data or remove an entire column of values, just select the column header (the letter at the top of the column), and press delete. This clears all the contents from the column at once.

That covers the basics of performing calculations and entering formulas in Excel. You can find a complete video tutorial with step-by-step instructions on everything discussed here on my website at the link below. Live long and prosper, my friends.

Topic List

How formulas work in Excel
Using the equal sign to start formulas
Referencing cells in formulas
Adding values from different cells
Viewing formula results and the formula bar
Editing formulas in Excel
Using basic math operators (add, subtract, multiply, divide)
Using constants and cell references in formulas
Exponentiation with the caret operator
Automatic recalculation when data changes
Deleting or clearing cell contents and columns

Article

In this lesson, you will learn how to perform basic calculations in Excel using formulas. Excel is not only useful for storing data, but it is also powerful for performing calculations on that data. Imagine you have sales data in Excel. You might want to quickly calculate totals for each month or each sales representative. To do this, you will need to understand how formulas and math operators work in Excel.

Let's start by experimenting with some numbers. Suppose you open a blank worksheet, and in cell A1 you type 10, then press enter. In cell A2, type 5 and press enter. Now you have two numbers that you can add together. In Excel, writing a formula is a little different from traditional math notation. Usually, you would see something like x plus y equals z, but in Excel you think about it as z equals x plus y. Z, in this case, is just the current cell you are working in.

Instead of using variables like x and y, you use cell references. So if you want to add the numbers in A1 and A2, you write the formula as =A1+A2 right in the cell where you want the result to appear. For example, click on cell A3 and type =A1+A2 then press enter. Excel will display the result, which in this case is 15. The equals sign at the beginning tells Excel that you are entering a formula. This step is very important. If you forget the equals sign, Excel will not recognize your entry as a formula and will just treat it as plain text.

If later you change the value in A1, for example changing it from 10 to 12, Excel automatically updates the total in A3 to reflect the new sum. This is because A3 contains a formula that points to A1 and A2, and Excel always recalculates formulas when the underlying data changes. The cell itself will always show you the result of the formula, but if you look up in the formula bar at the top of Excel, you will see the actual formula written out as =A1+A2. You can edit the formula by double-clicking the cell, clicking inside the formula bar, or pressing F2 on your keyboard. Excel also gives you visual feedback by highlighting the referenced cells in different colors, so it is easier to see which cells are included in your formula.

You are not limited to just addition in Excel. To subtract the value in A2 from A1, edit the formula in A3 to =A1-A2 and press enter. The result will now be the difference between the two cells. For basic math operations, here are the operators you should know: the plus sign (+) for addition, the minus sign (-) for subtraction, the forward slash (/) for division, the asterisk (*) for multiplication, and the caret (^) for exponentiation, which means raising a number to a power.

So, if you want to multiply A1 and A2, enter =A1*A2 in cell A3. If A1 holds 12 and A2 holds 5, the result will be 60. You can divide values too. Try typing =A3/10 in cell A4. If A3 contains 60, this will show 6 in A4. You are also allowed to mix cell references and actual numbers in your formulas as needed, which gives you flexibility for different types of calculation. Excel does not care whether your cell references are in uppercase or lowercase, so typing =a3/10 works just as well as =A3/10.

If you want to calculate exponents, for example squaring a number, enter something like =A4^2. If A4 has the value 6, the result will be 36, because 6 squared is 36.

When you are finished experimenting, you can clear out all the data easily. To delete all the data from an entire column, click the column letter at the top (for example, A) to select the whole column, then press the delete key. This is called clearing a range of cells and will erase everything in that column.

You have now seen how to perform basic arithmetic in Excel and how formulas automatically update when you change the underlying data. Remember to always start your formulas with the equals sign and use the correct math operators for the calculation you want to perform. With these skills, you can build more complex calculations and start analyzing your data more effectively.