We all know what a tab is, right? It's that key near the upper left-hand corner of the keyboard we press to indent the first line of a paragraph.
Sometimes, though, simply moving the cursor over half an inch isn't what we want.
Take, for example, something like this:
Those numbers look okay -- they seem to line up pretty well. But how did this person get this result? Let's turn on Show/Hide (that paragraph symbol on the Home tab in the Paragraph section) to see the codes:
Ah, I see. This person used Left Tabs (the default tabs you get when you hit the Tab key) to move the cursor to the left (signified by the left-pointing arrows above), then hit the space bar (the dots above) to get the numbers to line up.
But how well do they really line up? Let's turn on the gridlines (found on the View tab) to see:
Oooooh. Those numbers (and decimals) don't line up so well after all. But what else can you do?
Decimal tabs allow you to fix the point on the line at which the decimal will appear. When you hit the Tab key to go to a decimal tab, you start typing the number, and the cursor stays in place while the digits ahead of the decimal point (such as dollars) move leftward. Once you type the decimal, the cursor then moves to the right as you type the digits behind the decimal (such as cents).
It's probably easier to show you than tell you:
[Note: To view full-screen, click the button in the lower right-hand corner]
This is a basic introduction to decimal tabs for those who (a) didn't know they existed or (b) were too intimidated to try them. There are more advanced strategies for managing tabs in documents, particularly if you have the Ruler turned on in the View tab like so:
... but that's a tutorial for another day. This will at least get you started with getting your decimals all lined up!