PERTS Elevate Resource Library

My Favorite Mistake

Select an anonymous student solution and discuss as a class what the student understood well and identify a misstep to correct and learn from it together.

Grades 6-8, 9-12 Math Video · 1:37

Overview

My Favorite Mistake is a formative assessment strategy that helps students view mistakes as meaningful and valuable opportunities for learning. Rather than focusing solely on correct answers, this practice builds confidence, promotes peer analysis, and deepens understanding by exploring misconceptions together.

Through this practice you will be able to:

  • Spot common math misconceptions and use them to guide instruction.
  • Help students see mistakes as a normal and valuable part of learning.
  • Encourage discussion and peer learning through shared error analysis.
  • Build a classroom culture that values thinking over just getting the right answer.

Materials

  • Half sheets of paper or index cards
  • A problem or question suitable for individual quick written responses
  • Document camera, projector, or whiteboard to display the selected student response
  • (Optional) My Favorite Mistake: Student Work Analysis Sheet

Day Before Prep (~50 min)

  1. Select a math task (5-10 minutes): Select a problem related to a current or recent topic that represents the key objectives of the unit or standard. Ideally, the problem will contain strategies or concepts that students often make mistakes on or have misconceptions about.

  2. Solve the task yourself from a student's perspective (5 minutes): As you work through it, ask yourself:

    • What strategies might students use?
    • What concepts or steps could be confusing?
    • Where might students get stuck or offer unexpected ideas?

  3. Reflect and plan (10 minutes): Take a few notes and bring them to class as a guide. The goal is to anticipate student thinking and create space for meaningful mathematical discussion.

    • What questions will you ask to promote deeper thinking?
    • Jot down ideas for what you anticipate as common mistakes that would need to be further addressed.

  4. Prepare Materials (5-10 minutes): Prepare slips of paper, index cards, or digital tools for anonymous student responses.

  5. Plan the Discussion (10-15 minutes): If you're new to the practice, create a script or prompt for guiding the discussion so it stays strengths-focused and nonjudgmental. Reference the My Favorite Mistake: Student Work Analysis Sheet for ways to have students reflect.

    • Optional: Consider preparing a "Mistakes Help Us Learn" anchor chart to reinforce the purpose of the activity.

Conducting the Practice (~20 min)

  1. Introduce the practice (1 minute): Explain to students that today's goal is to see how powerful mistakes can be for learning and to work on being less embarrassed or worried about making mistakes. Here is sample language:

    "Today we're using a routine called My Favorite Mistake. It helps us move from fearing mistakes to being curious about them. We'll look at a mistake together; not to judge it, but to learn from it and strengthen our understanding."

  2. Pose a Problem (5 minutes): Present a problem for individual work. This could be introduced as a warm up activity or as a check your understanding moment during class. Students complete it quietly and submit their responses. Inform students to not include their name.

  3. Sort the Responses (1-2 minutes): Quickly sort responses into correct and incorrect piles.

  4. Choose Your Favorite "Mistake" (1 minute): Select a wrong answer that is not just incorrect but interesting. Look for one that shows partial understanding, reveals a common misconception, and invites deeper discussion. Perhaps it's one that shows up more than once. Your "favorite" should help move learning forward by highlighting what the student did well and where their thinking can grow.

  5. Display and Discuss (5-7 minutes): Project or write the response anonymously. Consider copying down the incorrect work on a separate piece of paper to avoid students being able to decipher hand-writing.

    Ask the class:

    • "What's right about this?"
    • "Where do you think the error happened?"
    • "How could we revise this?"
    • "Did anyone else make this mistake?"

  6. Summarize Learning (3 minutes): Clarify the mistake and highlight takeaways. Reinforce that identifying and discussing errors is part of mathematical growth, such as by saying:

    "By looking closely at this mistake together, we practiced one of the most powerful ways to grow in math—learning from our errors and mistakes and using them as stepping stones to deeper understanding."

Pitfalls to Avoid

  • Focusing only on what's wrong: Always start with what the student did well to maintain trust and confidence.
  • Revealing the student's identity: Keep responses anonymous to maintain psychological safety.
  • Rushing the discussion: Give enough time for students to analyze and reason through the mistake.
  • Overusing the strategy: Use "My Favorite Mistake" regularly, but not so often that it loses its impact or students feel overexposed.
  • Choosing overly simple mistakes: Select errors that are thought-provoking and allow for rich discussion, not just computational slips.

What to Look For

  • Students actively identifying correct reasoning in an incorrect answer
  • Positive body language and engagement when discussing anonymous work
  • Peer-to-peer discussion around misconceptions and revisions
  • Increased student confidence in participating, even when unsure
  • A shift from fear of mistakes to curiosity about them
  • Students being willing to share when they made a similar mistake

Additional Inspiration

This practice was developed in collaboration with WestEd.