Product IDs, serial numbers and other reference numbers require a unique identifier to avoid confusion when referencing a product or specific data point. Although you can manually enter unique numbers ...

Excel considers dates and times as numbers in cells, making calculation difficult. Excel processes 6 AM as "0.25," because it is one quarter of the way through the day. If you need to add a number of ...

You can subtract in Excel by placing a minus sign in front of any numbers you want to deduct. You can add and subtract a bunch of numbers at once using the equal sign or SUM function. You can add and ...