If you don't know how to subtract numbers in an Excel XLS worksheet, a simple formula will do the job for you. If you plan to create longer formulas that contain other operations (like multiply or divide), it's important to know how Excel handles the order of calculations (also known as order of operations). This way you'll get the results you expect.
The instructions in this article apply to Excel 2019, Excel 2016, Excel 2013, Excel 2010, Excel for Mac, and Excel Online.
Understand Excel Formulas
To subtract two or more numbers in Excel, create a formula.
The important points to remember about Excel formulas include:
 Formulas in Excel always begin with the equal sign ( = ).
 The formula is always typed into the cell where you want the answer to appear.
 The subtraction sign in Excel is the dash (  ).
 The formula is completed by pressing the Enter key.
Use Cell References in Formulas
Although it's possible to enter numbers directly into a formula (as shown in row 2 of the example below), it's usually better to enter the data into worksheet cells and then use the addresses or references of those cells in the formula (see row 3 of the example).
When cell references are used instead of the actual data in a formula, the data in the formula can be changed later by replacing the data in the cells. This way, you won't have to rewrite the entire formula. The results of the formula update automatically when the cell data changes.
Another option is to mix cell references and actual data (see row 4 of the example below).
Subtraction Formula Example
As shown in the example, the formula in cell D3 subtracts the data in cell B3 from the data in cell A3.
The finished formula in cell D3 is:
The result when you press Enter is 5, which is the result of 10  5.
Point and Click on Cell References
It is possible to type the formula into cell D3 and have the correct answer appear. But, when you use point and click to add cell references to formulas, you'll minimize the possibility of errors that happen when the wrong cell reference is typed.
Point and click involves selecting the cells containing the data with the mouse pointer while you're typing the formula. When you select a cell, that cell reference is added to the formula.

Type the equal sign ( = ) into cell D3 to begin the formula.

Select cell A3 with the mouse pointer to add that cell reference to the formula. The cell reference appears after the equal sign.

Type a minus sign (  ) after the cell reference.

Select cell B3 to add that cell reference to the formula. The cell reference appears after the minus sign.

Press the Enter key to complete the formula.

The answer 5 appears in cell D3.

Even though the answer to the formula is shown in cell D3, selecting that cell displays the formula in the formula bar above the worksheet.

You now know how to use cell references in an Excel formula.
Change the Formula Data
To test the value of using cell references in a formula, make a change to the number in cell B3 and press Enter. The answer in cell D3 automatically updates to reflect the change in data in cell B3.
A common mistake is selecting outside of the formula cell to leave formulaediting mode. This inserts the selected cell into the formula. Instead, when you're done editing a formula, press Enter to leave formulaediting mode.
Order of Operations (Using Parenthesis)
Excel has an order of operations that it follows when evaluating which mathematical operations to carry out first in a formula.
Excel follows the standard math principles of the order of operations:
 Anything inside of parenthesis is calculated first.
 Multiplication and division are performed next.
 Addition and subtraction are calculated last.
If you prefer to subtract two cells in Excel before multiplication or division, add parenthesis around the subtraction.
In the example, placing A3B3 inside parenthesis before /A5 subtracts 5 from 10 before dividing by 20.
The result of this formula is 0.25. If the parenthesis were not used in this formula, the result would be 9.75.
Create More Complex Formulas
To expand formulas to include additional operations (such as division or addition) as shown in row seven, continue to add the correct mathematical operator followed by the cell reference containing the new data.