“It’s Killing Me. I Gotta Know.”

Frank Noschese, on last week’s ceiling fan:

I’m dying to see the third act.

Ginny, a participant in my qualifying study at Stanford, on the water tank:

I’m dying of curiosity. Is that anywhere near the right answer?

Andrew Stadel’s student, on the path of the basketball:

Can we watch the video to see if he makes it? It’s killing me. I gotta know.

All three describe the experience of not knowing the answer to a math problem as something like death. A math problem. How does that happen?

My best guess? You start with a credible document of the world your students live in. That could be an actual water tank in the classroom or a representation of a water tank on video. It has to be credible. Then you document something happening — the tank filling, the fan spinning down, the ball sailing through the air — long enough for a learner to have a sense of what is happening and what might happen next.

That’s where you end the document. Then work happens. The work is motivated in part by the student’s knowledge that the answer actually exists, that the teacher talks a huge game about math being everywhere and in everything and we’re about to put that to a test.

Then you show the answer.

Please watch this video of Ginny watching the answer to the water tank problem. This moment was incidental to my actual research question. I have no way of knowing if Ginny would have experienced the same mixture of suspense, elation, and catharsis reading the answer to the same problem in the back of her textbook. I only know that if you had told me in my first year teaching that suspense, elation, and catharsis were possible reactions to a math problem, as much as I loved math myself, I would have thought you were crazy.

Previously: You Don’t Have To Be The Answer Key, Handle With Care.

2012 Oct 2. Rachel Kernodle writes about Bean Counting: “… the 4 groups that correctly got the extension with no help from me literally SCREAMED and high-fived each other when I played the answer video ….”

2012 Oct 2. Chris Robinson writes about Taco Cart: “More student comments from @ddmeyer ‘s Taco Cart #3act: I’m losing sleep over the answer, this problem is killing me. Teachers, #3act works. Students made me replay the answer to @ddmeyer’s Taco Cart #3act so they could provide play-by-play in the style of a horse racing announcer.”

I'm Dan and this is my blog. I'm a former high school teacher, former graduate student, and current head of teaching at Desmos. More here.


  1. Don

    March 12, 2012 - 7:34 am

    Just to be the total buzzkill, is there a different threshold to cross with folks who, perhaps, don’t have that level of excitement about solving a puzzle?

    I’m wondering whether that trial is checking top performers, folks who have already gotten a grounding in life that has taught them how to get a thrill out of Getting It Right.

    Is the representation+happening+mystery enough for a reluctant learner? Do there need to be some more stakes beyond the question of whether or not they figured it out?

    I’m not trying to make perfect the enemy of good here, I’m just wondering if there’s a dividing line and whether there might be components that make a representation motivating to 60% vs 100% of an audience.

  2. Dan Meyer

    March 12, 2012 - 8:01 am

    All fair questions. Like I said re: Ginny, this is just anecdotal and I don’t have any kind of strong controls here. I can say, though, that I taught students for whom “don’t have that level of excitement about solving a puzzle” would be an understatement and saw similar results.

    See also: Handle With Care.

  3. JJ

    March 12, 2012 - 8:16 am

    My objection is somehow different:
    How do you change your student’s killing feeling into “Oh, I have to do this on my own”
    That objection cames from my former experience in getting my own students engaged in watching the solution of puzzles, teasers, average problems (sometimes)… but hardly ever engaged in getting to the solution.
    Greetings, Dan, reading your ideas is always a pleasure (and sorry for my bad English)

  4. Matt Vaudrey

    March 12, 2012 - 9:19 am


    I saw you at … some conference in 2010. You mentioned that, in a given class, roughly 20% of the math can be from perplexing, real-life problems, but the other 80% has to be what you called “pure math”.

    I taught simplifying rational expressions today. We went over the lesson on whiteboards with increasingly difficult practice problems, then played a matching game.

    Do you still hold that the 80-20 mix is pretty sturdy, or do you think someday a real-life rational expressions problem will be a part of 3-Acts curriculum that I can buy on Amazon?

  5. Dan Meyer

    March 12, 2012 - 11:00 am

    Here’s John Scammell on the ceiling fan video:

    I had a class of non academic 10th graders absolutely riveted on the answer video to that one. Wish I had filmed them.

  6. Timon Piccini

    March 16, 2012 - 11:13 pm

    I am trying to figure out one glitch. I notice I get students asking an interesting question, wanting to know the answer, but still not motivated to do the math behind it. I wonder…

    Am I not selling it right?

    Am I not scaffolding it right?

    Or am I not preparing my class to be motivated right?

    Or is it all of the above?

    How do I fix this?

    I have also noticed entire classes can have a totally different mindset. My homeroom loves this stuff, but the other class I have are not very engaged (they like rote processes and textbook work). I feel I have the prep down, but I still can’t teach this well.

  7. Andrew Stadel

    March 17, 2012 - 9:00 am


    I hear ya man. When I did my first 3 Act lesson, I was expecting all my classes to be engaged like no other (that was naive). It took some adjusting and some reevaluating, but I learned from that first lesson to improve for the second. I learned that delivery, enthusiasm, and my interest are all important ingredients. I could show them a video of the most amazing thing in the world, but if I get too involved, they quickly abandon their excitement or motivation. If I fault them for not having the same interest as me, I’ve lost them. I found leaving little gaps of silence after the video, or playing dumb when asked a question antagonized the students just enough to want to know more and find out. I challenge the students to find an easy way to the solution because I think my solution is too long, laborious, or difficult and they can do it better. I found that getting really enthused about a student’s “first question” can help ignite others to share their question.

    Graphic Organizer: I prepared a graphic organizer to accompany the learning, keeping students on task, and seeing how they structured their work.

    Yes, the dynamic of classes is insane. One section struggled asking questions, but could do the necessary math in Act 2. However, one section asked the best questions all day for Act 1 and listed the necessary information, but sucked at the math solution part. It varies, and I LOVE that. it keeps me on my game. If it was the same reaction every class, or the same level of motivation every class, I’d get bored too. I would lose my motivation to help students learn.

    Not sure I’m offering a simple fix, because I wonder the same questions you do. It’s an ongoing challenge that I welcome. My fix is to continue going in, learning from my students. I ask them as much as possible to explain what made this learning experience good/bad, boring/engaging, easy/difficult, fun/challenging, etc. They see that I am interested in their learning and their best interests. You can’t always win, but that’s not my goal. My goal is that they understand we’re in this together to learn from each other, and we’re always trying to improve (both teacher and student).

  8. Timon Piccini

    March 18, 2012 - 8:35 am

    Thanks Andrew. I think I am just impatient. I want o have these classes now, but I have to remember that I am going through a process just as my students are. I have a long life as a teacher ahead of me. I liked your idea of. Graphic organizer and I thought that might be too much direction, but I think Middle Schoolers could learn from that and still have an open activity.

  9. Dan Meyer

    March 18, 2012 - 1:11 pm

    You two seem to have this well in hand. I’ll just jump in to say that the second act is a lot of hard work. Will It Hit The Hoop? would be a total drag if I were having students work with pencil on paper, scaling their own axes, and solving for the equation of the parabola. The math would be inaccessible, the reward not worth the struggle. A perplexing first act, for me, is a prerequisite for students giving a damn about the work we’ll have to do in the second, but structuring that work is its own enormous challenge.

  10. BrianM707

    March 18, 2012 - 3:34 pm

    For me with every step along the way – initial question / what info do we need / actual calculations – it has helped to have a script in hand. The script is basically how I am going to prompt students who meet the intial problem with a level of confusion that dominates their perplexity. I think the script is important, because although we can all free style our responses, I think it is important to consider what questions student might have at each step along the way, and taylor our responses to be most effective.

    For example, in the Ticket to Ride – for students struggling to ask for the proper dimensions, or struggling to correctly calculate the area of the ticket, I always say “what would happen to the ticket roll if each ticket was very thick? (make hand gesture for how thick you’re talking about) Ok, now what would happen if each ticket was very very thin? (make hand jesture about how thin you’re talking about). So what is going to be an important dimension for how many tickets are in a roll?”

    I well defined script helps.

  11. Timon Piccini

    March 18, 2012 - 7:49 pm

    I like the idea of a script. I am working on my questioning skills, but I struggle with asking in such a way that leads students forward. A script would help with that. How do you pro-stars use questioning techniques? Script them first? Are you just so familiar that you roll through?

    One Pro-D I would love to do is an anyqs tweaking session, especially which focuses on questioning. I don’t know how many people are familiar with High Tech High’s project tweaking protocol but it would be amazing to take some 3-Act lessons and collaboratively tweak.

  12. Dan Meyer

    March 20, 2012 - 10:18 am

    @Timon, hook up some details on HTH’s project protocol, okay?

    In my PD, FWIW, the first hour is spent doing a three-act task. The second hour is spent creating a script of teacher moves. Here’s the current example from El Paso, where I am this very second. It’s possible to speak generally about good things that happen in act two but it is impossible to script as far as I’m concerned.