My nikon d70 keeps saying 304 and when i press the shutter button it changes to r 12?

It also won't let me look at the pictures that i have already taken… I just want to know what this means and how to fix it.

First of all, the r 12 means that you can take up to 12 more shots before you have to stop shooting in the continuous mode

As far as the 304, you need to call Nikon and ask, unless the 304 is located next to the R 12 and then that tells you how many more image files you can save to your memory card.

When was the last time it was that you opened your user manual?

For now, remove your memory card and using a card reader, copy all your images to your computer to a new file folder named for the subject and date of your image files.

Next after all of the files are safely on your computer, format the card using the format feature on your camera (page 212)

Take a few shots and see if you can use the "Playback" button to view your images.(page 5)

There's nothing wrong with your camera. As said above, r12 means how many photos the buffer can hold if you use a rapid shutter. If you put the camera into rapid shutter mode and take a few photos, you will see that number decrease as the buffer fills.

Also, if you change to RAW or RAW + JPG, you will see the r12 go down to a lower number as those modes require a transfer of more data, which fills the buffer quicker.

A major difference between DSLRs and compact cameras is the existence of a FIFO buffer on DSLRs, This is a fast buffer that holds the photos as you shoot, then sends those photos to your slower memory card.

And 304 is probably an estimate of how many photos can be put on the memory card.

Take a picture. If you can then there's no problem. Read the manual.