my tablet is not using my external SD card for storage
I also have the A727. :)  

It appears that whoever designed the system should have been more careful with how he named stuff -- the internal hard drive is called "sdcard," as you mentioned in your question.



To use the SD card on your tablet, you need to hit the "SD card" button on the top of the screen (using the built-in file manager), as in the picture shown below. There you can see the folder labelled "extsd" = external SD card. (as opposed to the internal one?)



Then, when you open that folder, you can access the files on your SD card. Enjoy! :)