Open Middle

What's Open Middle?

Each problem has multiple ways of solving, and sometimes, multiple answers. The often puzzle-like questions lend themselves well to collaboration and discussions of reasoning and mathematical thinking, perseverance, and creativity.

Students complete several interations of a problem while building mathematical understanding, identifying misconceptions, and ultimately, developing a greater depth of mathematical knowledge.

As an added teacher move, educators can prompt students to reflect on each attempt: What did you learn from this try? How will your strategy change on your next try?

Sample Problems:

Use the digits 1 to 9, at most one time each...

More Information

Find these problems and prompts at

In this post, the creators of Open Middle, Robert Kaplinsky and Nanette Johnson, explain the structure of these problems.

Along with the K-12 Math Task Collection with selected Open Middle questions linked to SK outcomes, here are other resources:

  • Editable Google Slides for tracking student thinking

  • Use the search field on the Open Middle website to find alternate problems

  • Borrow the book Open Middle: Problems that Unlock Student Thinking (Robert Kaplinsky) from the board office

  • Open Middle worksheets are available on the site for tracking student thinking (English and French)

Available webinars for self-directed learning:

PD via Twitter: @openmiddle, @robertkaplinsky

Note: Selected Open Middle style problems have been converted into Desmos Activities.