Thanks to Andy Zsiga for the submissions. He’s wondering whether anyone has perspective on why students would graph several points correctly, and then mess up the point that contains a zero as one of its coordinates.

For the second example, the student has incorrectly plotted both of the points that don’t have a y-coordinate of 5. The thing that puzzles me about the first one is that the question specifically states that you are supposed to end up with a parallelogram.

Amy

I think their understanding is fragile. As a 7th grade teacher, I see this all the time. The (0,y) always messes a few students up, and it’s like once they flip it for that particular problem, they flip it for everything following. As far as the comment about the parallelogram, I think the students that make these mistakes are usually not students who think a lot about what they are doing. If they were, they would ask themselves, why isn’t this a parallelogram? OR they don’t even know what a parallelogram is! Students are used to MOVING right or left and then MOVING up or down. If they don’t get to MOVE right or left with the first number, they still automatically move right or left based on the second number.