If there are nine people in a room and every person shakes hands exactly once with each of the other people, how many handshakes will there be? How can you prove your answer is correct using a model ...

Editor’s Note: Janet English, Academic Coach for El Toro High School in California, spent six months in Finland on a Fulbright Distinguished Award in Teaching. While there, she discovered a tool to ...

Why should we care about problem solving activities for high school students? What’s the fastest way to get to and from work? How can I complete a task more efficiently? What should I have for lunch ...