Seeing the look on student faces as the video plays makes the problem. Seriously! What is that guy doing? (This is a Dan Meyer 3Act Problem – please see link for original problem and video.)

I ran two versions of the problem in class. Due to a testing schedule and late arrival of many students, my first class’ time was whittled down to 30 minutes. We’re getting into a rates & proportions unit and a goal was to connect back to work done in sixth grade to continue getting a feel for where my students are meeting me in the class. So, the problem unfolded generally as given in the 3 Act flow. There was high engagement at first but then the problem was solved immediately. Woops – good thing that the class was a short one! However my next math class of the day was a full length class (80 minutes) so reworking was needed. Here is the new flow and it provided for a better lesson where students were more engaged and actively discussing mathematics for an extended time.

The hook – got ’em.

Immediately after playing the video, student tables were given a red and an orange card tent and asked to come up with an estimate that was “too high” and one that was “too low”. We stretched a clothesline across the room and members of each group came up to begin placing their tents on the line. The clothesline is a great tool for these problems as students work together to sort their estimates along the line. Students then gave a quick explanation for their team’s estimate. The best was the estimate of 50 packets of sugar due to someone’s little brother who once put lots of sugar into a drink and a “stickiness” scale was developed…

So far, the problem is unfolding as the 3 Act is laid out. The next step is the shift. Instead of providing the given nutrition level, I grabbed multiple nutrition labels from the Coke site. The intent here was to have students work with more data. Does Coke keep the same proportion of sugar in each size beverage?

Multiple labels were printed and placed about in the room. For the smaller sizes, the serving size changed but for 1L and up, the serving size was based upon 12 oz (360 mL). This led to great small discussions as many students did not understand how to read a nutrition label and what a serving size meant.

Compared to the first pass of the problem, students were now up and out of their seats collecting data from the different nutrition labels. Their target had shifted as students now needed to determine whether or not all Cokes are created equally. Yay – we now had a need for determining the unit rate. (Interesting side note – the 7.5 oz bottle does seem to have a higher sugar content if you are looking for a sweeter Coke.)

For me, the shift in the problem opened up the class to a higher level of activity and discussion. I appreciate the window this gives me to have more conversations with students. Working through the nutrition labels resulted in a good stretch for some students. My weakness in wrapping up and really pulling out key understanding through class discourse showed itself again and I’m back to reading the book below. Processes that others have for wrapping up a 3Act task to pull out the learning for students would be much appreciated.

Love the extensions, Frank. I’ve updated the task with a link to your post.

Thanks for giving a look!

Great reflection, I was just tweaking mine from last year and I love what you did with the unit rate aspect? Thanks for the tips!

Awesome! If you get any other ideas, please let me know.

this reminds me of a task that Michael Fenton once did comparing the amount of sugar in a 12oz can and then scaling it up to a 20oz, 32 oz, 44oz and 64oz.

As for the discourse, what about having a student place their solution on the clothesline. Before that student gets to present their solution, the class has to think about why they may have made that guess. If the goal is ratios and proportions, then we need to take the student ideas and convert them into an equation that they help us build, rather than us tell them what the equation is.

Thanks for the suggestion. I’ll try to work that one in this year.