Arranging photos in a tablet running 2.1

[NaloJeff]

I just got a "Nextbook" running Android 2.1. I'm trying to put photos on an SD card, and have them play in a certain order so I can show them in a slide show. When I arranged them in a folder on my pc, I gave each photo a number so they would display in that order. However, when I copy them to the SD card, and try to play them on the tablet, they appear in a different order. How can I get the photos arranged in the order I want? Thanks in advance.