Wednesday, August 2, 2017

Practice Structures: Error Analysis Revisited

Last summer I wrote about using error analysis as one of my favorite ways to practice math skills.  Since then I've found a few more resources and created a few more that I'd like to share.  In general, error analysis activities involve purposefully making common mistakes, then having students try to find them.  Here is a link to the original post if you'd like to see it.  In that post I shared an example for the segment addition postulate and midpoint as well as a second example for multiplying polynomials.

Here are some other examples that I found.  I did not create these.
Grade 2: Adding and Subtracting up to 3 digits.
Grade 8: Solve Linear Equations.
Algebra 1: Graphing Linear Inequalities in two Variables


  1. Thanks for this! Do you know Michelle Pavlovsky? She does something called Mistake Monday, and she makes a lot of error analysis problems for Grade 8. I believe this twitter thread contains a link to her folder of error analysis activities:

    You might also check out Algebra by Example? I've found their stuff useful for my Algebra 1 students. (Though I don't actually know what grades you teach!)

    Thanks again for the post! I've loved the entire "practice structures" series.

    1. Thanks for the kind words! I checked out Michelle's folder; what a treasure trove! I love Algebra by Example, but keep forgetting to use it as often as I should. I keep hoping they come out with other high school subjects!

    2. I had this dream that over the summer I'd make a lot of Geometry by Example tasks, or that I'd go through and start turning those into Algebra by Example-style activities...

      ...that didn't happen. Maybe next summer!

    3. That would be awesome :)
      I did buy this book this summer. It is short but has some good error analysis.

    4. Ooh, amazing! Maybe I'll get myself a copy. Though what I like so much about Algebra by Example is that it's a mix of right/wrong examples, I can always use more error analysis material.

    5. Actually, most of the pages in the book have about 4 problems on them. The directions usually say something like "At least one of these solutions is correct and at least one is incorrect."