These cards can be used to manage classroom participation. There are times that a few students tend to "control" discussion or are always participating. Using these cards can help maintain a more equal balance while also encouraging students who do not always participate.
*I use a calculator holder and place the cards in there. Each student is assigned a number in my classroom. The students move their card from the calculator holder to a bucket after they participate (in a positive way). Once their card is moved, they need to allow others the opportunity to participate as well. I collect the cards at the end of the class period and mark their participation.
You could also use these cards as a way to take attendance. Have each student collect their card at the beginning of class (you know who is absent by what cards are left), and give you their card after they participate.