1. Open the Numbers application, create a new spreadsheet or open an existing spreadsheet.

2. Select a cell in the spreadsheet and enter a number.

3. Select another cell and enter another number.

4. Select Formula in the menu bar, and then select Add Formula.

5. In the pop-up dialog box, select the first number cell, then enter the minus sign, and then select the second number cell.

6. Click OK, and the result of subtraction will be displayed in the new cell.