I have wondered for quite some time now what the number to the outer right in my 450D's viewfinder is.
30" 2.8 |''|''|''|''| 100 6
what's the 6 stand for?
It looks like you might be asking about the maximum burst number. It tells you how many pictures you can take before the buffer is full. As you take pictures, the number will go down, and it will go back up as the buffer clears to the memory card. Taking pictures closer together (or using continuous) will deplete the buffer faster.