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

One simple rule can help solve any complex equation. Here's a hint: all it takes is a catchy acronym.

Solve word problems using a checklist. Engage in a Number Talk to find "how many." Solve addition and subtraction word problems with a Step-by-Step Visual Model checklist. Understand what the problem ...

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 ...