Research tells us sutdents need numerous and varied exposures to new vocabulary words. I made the cards through the Scholastic "Make Your Own" service. I use the cards to review place value vocabulary. Pass out the cards to students and have them mix & find their match. Another option is to tape cards to student desks and call out their corresponding matches. I also use them on my math vocabulary word wall, taking them down throughout the week to conduct the various vocabulary activities.