[header] How to use your samsung galaxy tab as a phone [title] Check for sim card support. [step] Galaxy tablets have two versions: one that supports a sim card and one that doesn't. Refer to the tablet's user manual to see whether the android device you have supports the said feature or not. 
[substeps] You can also look around the sides of the tablet or behind its battery for any slot that a sim card might fit in. It's a small slot only a little larger than that of a memory card, and is very easy to find.