Get rid of those old flash cards and electrify math learning with these six sets of 50, two-sided, Hot Dots cards for use with the Hot Dots Power Pen (sold separately). Each card features an equation with possible solutions. Children respond by pressing the Power Pen on an answer dot - correct answers are rewarded with lights and sounds from the Pen, or a Booing for incorrect ones. May also be used as conventional flashcards. Grade level: Preschool+. From Educational Insights.