I recently returned to teaching after an extended maternity leave. As much as I love my girls, it was tough for me to be out of the classroom for almost a year. A lot can happen in a year and a lot did happen in a year in our math world. We adopted a Singapore inspired program, embraced the mathematical practice standards, and had Yeap Ban Har train us in a better way to teach math. It was at Ban Har’s workshop where my mind truly experienced a renaissance, if a mind can experience such a phenomenon. Of course, by the time Ban Har reshaped my focus I had already been trained via staff developers of the Math in Focus program. Every lesson structure we discussed and I witnessed allowed little light bulbs in my head to flicker. When I returned to my classroom this past August, I was determined to change everything.
Anyone who has been in teaching will tell you that changing everything, for lack of a better term, is stupid. As true as that may be, I knew the type of math teacher of which I was aspiring to become, so I attempted such a transformation. I furiously researched my new textbook topics and scoured the Internet for lessons that were already brilliantly designed and would complement the objectives I knew I must meet. It was this search that led me back to Dan Meyer.
I had seen Mr. Meyer’s Ted Talk discussing how math instruction must change. But like most people, I need to be introduced and reintroduced to something multiple times before I truly embrace and understand it. I re-watched Dan Meyer’s Ted Talk and then went further to watch examples of his 3-Act Math. In a nutshell (apologies to Dan Meyer here for not doing this explanation justice), three act math includes a conflict/hook, a problem where students must develop ways to overcome the obstacles presented, and a resolution. There are various ways to get that hook, and it is our job as instructors to find it and lead our students’ interest in our direction.
Upon searching for something to do with integers and absolute value, I came across one of his lessons that had students guessing ages of celebrities. Like all teachers out there, I “stole” his idea, and modified it to make it my own. I spent hours debating which celebrities to use in my presentation and how many I needed. Then, realizing that I would be at a different pace with each of my classes; I figured I needed to make at least two versions of this lesson so the celebrities would be different for each class.
Here is what happened in my first class.
I asked the students how good they thought they would be at guessing somebody’s age. The responses varied from, “I am so good at that, to, I am the worst.” After they polled each other quickly on their anticipated success or failure at such a task, I posted a slide with lots of celebrity pictures with the challenge: Let’s examine your talents. On the slide, I showed Barack Obama, Daniel Radcliffe, Donald Trump, Oprah Winfrey, Selena Gomez, Serena Williams, Michael Strahan, and Tom Brady.
Next, I distributed a table with the following categories: Name, Age Guess, About, Difference.
I then posted one slide at a time of each celebrity and the students had about 30 seconds to record their age guess.
The students were excitedly shouting out their guesses and arguing with each other as each celebrity was shown on the screen. After they recorded their guesses, I posted the actual age of each celebrity in a table that matched the one I created for them. After they filled it out, they were instructed to determine the difference between the actual age of the celebrity and their age guess. We figured out who was the best in the class at this game and who was the worst guesser. Both students were celebrated by a round of vigorous applause. The discussion led to the fact that there was never a consideration as to whether the guesses were too high or too low, just the distance from the actual age.
Eventually, students figured out that this was an example of absolute value because they were measuring the distance from the actual age.
Students were then asked the following question: “If provided the exact birthday of any of the celebrities from the previous slides, how could you find a more precise difference between your guess and the actual age? For example, Donald Trump’s actual birthday is June 14, 1946. Use this information to find a more precise difference between your guess and the actual age of Donald Trump. Discuss, explain, and problem solve.
Students soon realized that they were dealing with rational numbers. Some students decided to post the information in fraction form out of 12 months, others used 365 as the denominator and were showing the age difference to the exact day, and still others tried to tie in hours! They were all on a mission to be the most precise and my classroom was alive.
Since that lesson, I have referred to the age activity when reminding students about the concept of absolute value. This lesson became one of those lessons. The lessons teachers dream about. Students were inspired to perform all of the problem solving, research, and data gathering independently and collaboratively, without much from me. Most of my work was in the lesson structure and observation. The rest was up to them.
That was a good day.