So yes, there are blank sides where there are usually pictures. I used these when I was tutoring children, and I took stickers of whatever they liked and used those to represent the numbers. For example, a little girl from China really liked princesses, so I made these flashcards with princess stickers and had her count how many princesses were on the card to get the answer. You can personally make these cards for someone, or you can turn this into a lesson where the kids personalize the cards themselves with markers, crayons, colored pencils or stickers. These are suitable for English language learners of all ages and mother tongues.