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.
Category: Feedback
Categories
Lines Tangent to a Point
What does the student know? What doesn’t the student know yet?
This student knows stuff. What does the student know? Where did they go wrong, and why do you think they went wrong? How might you help?
What does the student know? What are the student’s misconceptions? How would you help?
Categories
Tangent Lines
We’re putting together a nice collection of Calculus work. Keep up the great submissions!
What does this student know how to do? Given what the student knows, what’s your best guess as to the source of the error? How might 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?