How I Get Students to Defend Their Math Work

One year I had a student teacher who was a former lawyer and wanted to leave law to become a classroom teacher. ... I'll let that sink in for a moment. ...

OK... moving on.

I had just graded an abysmal group of math papers where it felt like I was grading number roulette. Clearly, they didn't understand the concept, and I needed to reteach. No problem. That happens a lot with new concepts. But this was an ongoing problem with this particular group. OK, truth be told, it was a problem almost every year. Learned behavior - If I turn in a paper with something written on it, it's good enough. There was no ownership.

That was about to change.

The next math period, I gave them a problem to solve, first in group work and then on their own. Instead of our usual closing discussion, I threw them a curveball.

I told them, "Today, class, you are all Math Lawyers. You must defend your answers and convince me that you are correct."

What?!? Is she serious? What does that even mean?

We talked about what lawyers do. I closed with, "If your answer is correct, you believe your answer is innocent (correct), and you will be able to defend it.

Silence. I was OK with that.

I assigned the problem as homework so they had a chance to really take a look at their client and create a defense that they would present the next day.

The following day... 

I explained how this would work by modeling a volunteer's answer. I chose someone who was always sure of their work and was usually correct. They might sometimes hurry and make careless mistakes.

She placed her work under the document camera to present her "defense" of her answer. I was sitting at a desk up front, acting as the opposing "lawyer."

I asked her a few questions about different steps in her work. I asked if she determined it would work with a similar problem.

In the end, we both agreed that her work supported her solution, and her client was free to go. (She could turn in her paper.)

Once the kids saw how it worked, they were eager to either defend their answers or give them another look before turning them in.

Teacher Tips - Get the Ball Rolling

1. Give advanced notice that Math Court would be in session the following day. Then, break the kids up into groups of three. One student defends their work while the other two question parts that weren't clear and might be wrong. When they've all had their chance to defend their answers, they turn in work they're satisfied with.

2. Spot-check by asking, "Are you willing to defend this answer in Math Court?"  I do this when I see glaring errors or if I just think they need to take another look. They like having the opportunity to recheck it before turning it in.

3. Let them know the problem given to them that day will need to be defended in Math Court. This can be a good way to review for a test. 

4.  Give groups one problem they need to defend as a group.  This is another good way to review material that will be on an end-of-unit test. Each group gets a similar, slightly different problem they must defend. They are given a set amount of time to prepare their "arguments." They present their solution to the class. The class acts as opposing attorneys, asking questions for clarification.

I like this approach because it gives everyone a chance to participate. Even if I don't get through the whole class, the problems are similar enough to see similarities.

There are benefits!

It's no secret that kids love to role-play. As math lawyers, they're given a chance to see their work from another perspective.

Students look at their work differently when they think of it as defending something important.  It was fun to watch their transformation from students writing numbers on papers to, "I believe in this work,  and let me tell you why!"

Not only does it help kids own their work, but it also improves study skills.

Once they're comfortable with their new math lawyer status, this could be the test!

Give it a try!

Challenge your students to move beyond turning in "good enough" assignments to actually defend their work. Click here if you would like your own Math Lawyer poster set to get you started. Then let me know how it worked for you. 

And now... Court dismissed!