This post is brought to you by David Wees. Thanks, David!
Categories
Category: Grade 8
Why is this mistake so enticing, and how might you help students avoid it?
[Compare: http://mathmistakes.org/?p=396]
Thanks again to Anna Blinstein for the submission. Follow her! Virtually! Not literally!
Would the student have made this mistake if she were just given 
Oh, and go check out Chris Robinson’s stuff, and go follow him on twitter.
Where did this kid go wrong? What does it reveal about his understanding of solving equations? What is your next step for him?
The mistake is clear. Why is this mistake so damned tempting, and how would you help?
I’m sitting on a bunch of Khan Academy questions from users that I marked as very interesting. I never posted them, and I feel a little cheap giving them all their own posts. So I figured I’d just dump the whole lot on you all. These questions reveal interesting things about the way these students are thinking. If you think that you’ve got something interesting to add, either on the diagnosis or prescription side of things, dig into the comments below.
The first is a nice probability puzzler. How did this student get 3/8?
I love this conceptual question.
Not sure exactly why I clipped the first question here, but the second question is great. “Why do they call it a limit?”
A good reminder: some vocab is tricky. Why are these two vocabulary words the one that this student confused?
This is a great point from a kid about variable use.
A little bit of context for this next one: we’re talking about protractors here.
Categories
Backtracking
What does the student understand, and what does she not? How would you help?
What does the student know? What are the student’s misconceptions? How would you help?
What aspect of solving linear equations is this student struggling with? From the student’s point of view, why does the moves made seem like the right ones?
Are there any interesting things that you do to help students with linear equations? How do you make the right moves seem intuitive?
What is going through this student’s brain? What would you say to the kid to help out?
Let me know if you’re having trouble reading today’s submission. If image quality continues to be a problem then I’ll experiment with typing the student work up.