Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. Have you ever tried typing a complex ...

Richard Rusczyk, founder of Art of Problem Solving, has a vision for bringing “joyous, beautiful math” — and problem-solving — to classrooms everywhere. When Richard Rusczyk became interested in math ...