Get out your timer and number two pencil to see if your arithmetic skills are still sharp.

A new proof illuminates the hidden patterns that emerge when addition becomes impossible. The simplest ideas in mathematics can also be the most perplexing. Take addition. It’s a straightforward ...

Math is the sum of its parts, and it adds on itself. What does that mean? It means that multiplication is just repeated addition. And that mastering the times tables will help students simplify ...