This delightful hundred-chart game features a perfect balance of number patterns and strategic thinking.
“Connect Four” is an excerpt from 70+ Things To Do with a Hundred Chart: Number, Shape, and Logic Activities from Preschool to Middle School, which is available as an ebook at my publisher’s store (where you get all formats for one low price, and I earn higher no-middleman royalties) or through other online retailers, or by special request through your local library. Read more about my playful math books here.
The Math Game Monday posts will be available for one week only. If you missed this one, explore the links in the sidebar. There are more than forty free games scattered around the blog. Have fun playing math with your kids!
Denise Gaskins' Let's Play Math 
One of the best ever math games. I love how Joe introduces it, by showing some used gameboards and asking what they think the game is.
It’s a great game. And his blog post is wonderful for seeing how an idea grows into a game, and where it might go from there.