Sometimes, it’s better to let the students do the teaching.

That’s how I approached today’s lesson on adding and subtracting rational numbers. I know these lovely folks have added and subtracted a few fractions in their time, so I started today with an error-analysis twist.

First, I grabbed a stack of papers and told the students they were going to grade them, so they had better find a red pen. Next, I handed out a curious paper with “student work” on it – four problems to be exact – that had already been worked out.

Student: “Who did these?”

Me: “Well, they are technically in my handwriting to protect the identities of the students who originally worked the problems, but you are grading real student work.” (True story.)

Another Student: “How many points are these each worth?”

Me: “As many points as you want, you are the teacher, Miss ________!”

Furiously, the students began writing on the already-solved problems. Two problems were correct, so students gushed with praise over those… but the problems that were wrong? For those, they showed no mercy. None.

“SEE ME!”

“You NEVER, EVER add the denominators!”

“SEE ME! -1,000,000 points!” (This student was having just a tad too much fun being in charge of the point values, ha ha!)

“This is fun!” one student exclaimed, literally bouncing out of her seat.

Next, I had my “teachers” present their graded papers using the document camera, referring to each student as “Mr. ________” or “Miss ________”.

Amazing what a little role-playing can do to motivate students! It was fun to see their enthusiasm, and even better to see them identify correct and incorrect processes, giving constructive feedback that demonstrated procedural and conceptual understandings. Kudos to the teachers these students have had in the past – students’ prior knowledge has followed them to my class, and this activity brought that knowledge right out in the open in a fun way!

(Shhhh! A little secret – 8th graders still like to play!)

P.S. Thanks to a little app called Skitch, I can add the cool, colorful notes and arrows to the classroom photos I post here. Thanks to Lisa Johnson for introducing me to this handy, dandy freebie.

Here’s an error-analysis resource using QR-codes for feedback!