iPad - Update on App Store does not work? Any way to fix. Have shut down and done a hard reboot.

iPad model MD330LL/A. Software version: 6.1.3 (10B329)

My App Store shows I have 7 updates to install. When I go to the Update section of the app, the screen does not show any updates. Also the Update All button dos not appear on the upper left of the screen, but the Search Store button is still in the upper right. I have shut down the iPad and have also done a hard reboot (held down the Home button and the Sleep button) but this does not fix the problem. What do I need to do to fix this problem? Thank you