Card games are great for low cost fun and learning!
When I was very young, my Grammy taught me how to play gin rummy and a few other card games. I will always remember being amazed at how fast she could shuffle the cards!
I had graduated beyond WAR and Go Fish. Grammy was an avid gin rummy player, and she started me out on a 7-card variation (10 cards, the standard, was too many cards for me to hold in my little hand!)
Another game she taught me she called Casino, which required using simple addition, working memory, sequencing and patterning.
Not only did card playing teach me basic math skills like sequencing and making sets, it created a cozy twosome that I miss to this day.
Playing with Grammy was a way for the two of us to enjoy each other’s company. We didn’t care who won or lost. We never kept score. But on a rainy, otherwise boring day, it was a simple, no-cost, way to connect.
For most basic, kid-friendly card game rules, including gin rummy,
https://wehavekids.com/parenting/Card-Games-For-Kids#mod_45581387
For Casino: https://considerable.com/casino/