Here’s a simple number game to play on a rainy day, or while sheltering in place. You and I take turns crossing out numbers from the list {1, 2, 3, …, 9}. The winner is the last person to cross out a ...

Many years ago, a friend showed me this bit of mathematical trivia that thrilled us both no end: And then there’s the one I believed, for a while, was my own totally innovative discovery (it wasn’t).

Want to help your seventh-grader master math? Here are some of the skills your child will be learning in the classroom in seventh grade. At a “25% Off” sale, Marissa buys a skirt for $40.50. What was ...