Matt submits the above, and Matt writes, “I think it’s especially interesting that this student left the mistake on the board even though she had found the correct solutions by graphing in Desmos. I’m not really sure if she did half of forty, or sqrt 4 and then stuck a zero on it (she wasn’t sure either).”
I vote for “half of 40.” You?
What do you notice in this student’s work?
Thanks to Matt Owen for the mistake.
How worried are you about this mistake?
Thanks again to Tina! Go Tina!
What does this mistake reveal about the kid’s thinking? How would you take the kid’s thinking to the next level?
What does the student have right, and what does the student have wrong? How would you help?
As we start a new week of Math Mistakes, if you have any pictures of student work that you find interesting in any way, please send it in.
Today’s student has a couple of ideas worth drawing out. Do so in the comments.