In a recent BGG forum thread Defending BGG’s most hated games!, the thread creator called out the old card game War, the game we all played with our grandparents where two people draw from a 52-card deck and whoever has the highest value card wins them both. Like so many games that gamers (myself included) dislike, War has something to offer for the appropriate audience, young children.
War fits in with many math aspects of the Head Start Early Learning Framework. Children will first learn their numbers and quantities by looking at the number in the corners of the card and counting the symbols. Eventually, this numeracy will lead to the understanding that 8 is more than 4. Finally, children will be able to instantly identify the quantity of symbols in a small group with no need to count.
If you want your pre-K little one to get a head start on STEM, find a deck and remove the face cards. It is much cheaper than any STEM-teaching toy on the market right now.