No, not flash cards, although they can be useful, too. These are cards for card games that kids and parents or other family members can play together.
Playing cards also provides an opportunity to learn social skills such as asking politely, saying no acceptably, taking turns, sharing an activity, following rules and more.
Sometimes children win the game, sometimes other people win so children are supported as they learn to deal with competition and disappointment. These are important readiness skills, too, to help a child cope with all the social expectaions at kindergarten.
Go Fish, Concentration or Memory-(there’s not much competition when kids play with me; they beat me!)-even Old Maid, which I never win either, are a few card games. For younger munchkins use only a few pairs at a time.
Increase the number of cards as children become more proficient. Most of all, have fun! Ready, set, deal.