How many students are suspended each year?

Let's make this a math lesson. https://t.co/gVjol6PiI6

— Brian Aspinall (@mraspinall) July 26, 2015

I thought this was a great idea! Here are my draft ideas.

Act 1:

Students walk in and see these questions:

"How many students do you think are suspended each year in the entire United States?"

Write down a reasonable range as an answer. Include your reasoning.

Before we deal with Super Bowl stadiums full of suspended students, I ask them to first think about the total number of suspenions. I want to students to contrast their instinct with the reality. Contrast and conflict tends to leave an impression on the mind. If their instinct is on track, they will have confirmation (which is pretty great as well).

Although students may write a response to the prompt without any assistance. Others will want to ask for more information (which is exactly what I want). If they are making progress, I will let them talk it out. If not, I will stop individual students, groups or even the entire class and ask what they need from to make a reasonable estimate. Some students will ask for the total number of students, which I am willing to give to help them:

Total students: about 49.8 million (I might write 4.98 e 7 to stress scientific notation). 

Once students have decided upon a reasonable range of values, I ask them to write those numbers out on a post-it. One high number and one low. We can post these on the wall to see the full range of guesses and talk about reasonable guesses (something based on their anecdotal experiences) and unreasonable guesses (0 and 49.8 million). 

Once we have talked out our ideas, I show this stat, with a slight omission:

Students can share their observations and questions.  If they have a wide range of questions, I like to type them out on the board as they ask them. There is something wonderful about being quoted in class. Eventually, we settle on the main question, "how many stadiums would they fill?"

To answer the questions, students need to ask for:

1. The seating capacity of the stadium

2. The total number of suspensions

Act 2:

As expected, I found a wide range of Superbowl seating capacities. So I give a few samples:

They also need to know the total number of suspensions:

3.45 out of school suspensions

3.5 in school suspensions

Act 3:

As students consider how to count the suspensions (one type or both), I like to point out the ambiguity of the statistic. Many powerful messages omit the necessary details needed to assess the validity of the message. In this case, we don't know what types of suspensions they were considering and what size stadium they were using.

With the stadiums selected, they might get something like this (this table also shows how many stadiums would hold all students):

When I show the final reveal slide, we will know a bit more about the assumptions the authors of this sign made (Mercedes stadium is by far the closest to 45, if we only consider out of school suspensions).

Although the reveal of "45" may only be somewhat climatic, I image that the discussion afterward could be very rich. We could discuss the following:

• Why did they only include out of school suspensions?
• Why didn't they use a smaller stadium to maximize their number?
• Does this number still seem large if we consider that all students would fill 651 stadiums?
• What percent of students are suspended?
• Is this stat helpful or misleading?

Aside from the powerful social commentary available in this lesson, I would also stress the use of mathematics in modeling the situation. It is always wonderful to give students a chance to critique a model and the assumptions that went into it. In the process, they do something I always want them to do: decide what is reasonable for themselves. 

Sources:

Total school enrollment: http://nces.ed.gov/fastfacts/display.asp?id=372

School suspensions: http://www2.ed.gov/policy/gen/guid/school-discipline/data.html