How to Use Negative Numbers to Calculate in Excel

Calculating Negative Numbers
1. Enter a negative number into an Excel spreadsheet cell by using the minus sign (-) before the number.'-12' is an example of a negative number.
2. Use the arithmetic operator, the minus sign (-), to subtract a number using a formula.An example is the formula, '=25-10' that will give a result of '15.'
3. Use a function to calculate negative and positive numbers.An example of this is '=sum(a1:a3)', where cell a1=10, cell a2=12 and cell a3=-25 will give a result of '-3.'
4. Use a function to transform a positive result into a negative result by applying the negative sign (-) to the function. An example of this is '=-sum(a1:a3)' using the established values for those cells will give a result of '3.'
Change Negative Number Formats
5. Select a number or range of numbers to change the way Excel displays these numbers.
6. Click the 'Home' tab on the top menu and select the arrow in the 'Number' section.
7. Choose either the 'Number' or the 'Currency' category in the 'Category:' list in the 'Format Cells' window.
8. Select the number of decimal places by either typing it in or selecting the up or down arrow in the 'Format Cells' window.
9. Choose the 'Use 1000 Separator (,)' check box. Skip this if you are formatting currency.
10. Choose the currency symbol by clicking the down arrow in the box next to 'Symbol.' Skip this if you are not formatting currency.
11. Select the number format in the 'Negative numbers:' box in the 'Format Cells' window.
12. Click the 'OK' button.