The idea for the dot pattern cards came from Teaching Student-Centered Mathematics Grades K-3 by John A. Van de Walle and LouAnn H. Lovin.
Use these dot pattern cards as flash cards. Hold up a card for a few seconds, then see how many dots the students see. How did they figure it out? What did they see when they looked at it?
There are dot pattern cards for 1-10. The higher the number, the more dot pattern cards there are for that number.