How many pictures will hold on 56MB?

That depends on the file size of the photos. This is determined by your type of digital camera and the quality settings you use. Check your camera's manual to find out how the settings affect the file size/storage capacity. If you don't have the manual anymore, check the manufacturer's website for a pdf version... or just take a picture and check the file size, then divide your storage capacity by that number and you'll have a pretty good indication.