Read this chapter, which provides a visual tutorial on converting a table back into a list of data and then subtracting the data into "chunks."
If you have a list of data in Excel that has not been put into a table format, creating an outline
to help organize the data is easy. The first image below is an excerpt of the spreadsheet used in subunit 10.1.3: Filtering Data. Even though it looks like a table, these data have
not been put into a table structure because the Subtotal command, located on the Data ribbon, is still available.
In contrast, in the image below, the Subtotal command is not available because the list of data
has already been made into a table. Even though these two images look the same on the
surface, they are not. Notice the other greyed-out commands that cannot be used when a list
is in table format. This is not to say that a table format is less desirable - it is usually favorable,
but experience will help you to know when to use a table and when not to. Often, you can create and perform mathematical calculations on a table and then use the Convert to Range command to use the Subtotal command for optimal grouping.
Now, let's look at the Convert to Range command. Let's say I want to subtotal each product type in the table. First, I would sort the table by the Type field A–Z. Then, go to the Table
Tools Design toolbar and click the Convert to Range command (see the image below).
Next, a dialog box will pop up (see image below) to check whether you want to do
this. Choose Yes so the Subtotal command will be available on the Data ribbon.
Now go back to the Data tab and click the Subtotal
command. A dialog box will pop up, and you can decide
how to show the subtotals. You will Count how many of
each type (laptop, projector, etc.) are listed. For a hint,
use the example on the right, noting all of the selections made in each area of the Subtotal dialog box.
Below is the resulting subtotaled list. Note that each Type has a count listed for that
subsection.
This concludes our quick introduction to subtotaling.
Source: Saylor Academy This work is licensed under a Creative Commons Attribution 3.0 License.