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 ...

Sam Raskin has wrapped his head around a math problem so complex it took five academic studies — and more than 900 pages — to solve. The results are a sweeping, game-changing math proof that was ...