These playing cards use atomic mass, atomic number, and atomic symbol as the "suites". They can be used just like regular playing cards except with 3 suites instead of 4. I have used these in class to play the card game "spoons" to help students learn the first 20 elements of the periodic table, but they have many different potential uses. The pages are ordered back, front, back, front, etc. I would recommend using card stock and then laminating the cards, otherwise they tend to stick together. When printing, make sure that "fit to page" is NOT selected.