Just how high was the Big Thompson Flood? And how often will a flood like that occur?

Recently, the family and I were taking in an afternoon in Boulder, CO. After taking in a lunch at the lovely Dushanbe Tea Room we took a stroll along Boulder Creek. Right by a retaining wall stands this object.


This monument demarcates how high the waters rise for a flood of various magnitude. Zooming in a bit to the demarcations we see the following (from bottom to top):

Version 2

Version 2Version 3

The thing that makes flood levels so interesting mathematically is that in addition to height, they’re measured in probabilistic time. That is, every 100 years we can expect one flood to reach as high as the demarcation of the “100 Year Level”. Every 500 years we can expect one flood to reach as high as the “500 Year Level” and so on.

So… what does that suggest for the marker near the tippy top of this monument, marking the height of the Big Thompson flood of 1976?

Version 4


Suggested Facilitation

Provide the following (enhanced) picture.


Follow up with your favorite problem kicking off protocol. I’d suggest either a Notice/Wonder or a Know/Need-to-Know.

Potential Questions

  • How high did the water level get during the Big Thompson flood?
  • How often does an event like that happen?
  • How high are these markers off the ground?

For this last one, you’ll probably need some sort of base level unit to measure the heights, for perspective’s sake. Allow me to provide one additional picture.


(Hey, if it’s good enough for Stadel, it’s good enough for me.)

Guy racing another guy in a squirrel costume, obviously a systems problem


Entry Event: Only the first half of this video of some between-innings entertainment, like so:

(Editor’s note: I had to grab the video via a screencast, which doesn’t have the greatest resolution. If anyone can download the video directly, please let me know how. (See update below))

Suggested Questions:

  • Who wins, the regular guy or the guy in the squirrel costume?
  • How what is the distance of the race?
  • What are the dimensions of the field?

Suggested activities:

  • Provide students with the video and ask them to develop a mathematical model to describe both runners.
  • Graph those models.
  • Students will surely need/want to know the length of the race. Provide students with the dimensions of the park. Anyone know the width each of those little striped grasses?



Of course, the resolution of the story, the full video.

Update 1/24

Dane made a great 3-Act version of this activity, with better video capture. And made me jealous of his video editing software and acumen.

Update 3/26

I much preferred the video version that Dane procured, however I did like the original broadcast audio a bit better. So I stitched ’em together. What do you think? Like it?

Entry Event (Act 1)

Conclusion (Act 3)

Do violent video games cause violence? One Social Studies teacher’s experience teaching Math

(A lot of people have heroes. Many of those heroes are athletes or celebrities. For others, they are cops, firefighters, and teachers. One of mine is Lee Fleming, a co-worker, friend, and inspiration. Lee has taught Social Studies and Spanish. A couple weeks ago, she added “Math” to that impressive resume, despite never being formally taught math ed. She wanted to get her and her neighborhood kids ready for mathematics for the year and took it upon herself to review some math before the school year started.

I feel like we have a lot to learn from her experience, which is posted here, in her words.)



My Math Experiment with Tweeners:

So you can get the context for my math below, here is the email that I sent out to my friends in the neighborhood:

Parents of x middle school students,

I am sure you know that the state of Utah will be implementing the Common Core Standards and the kids will be experiencing a new set of standards for the year.  No matter what math they had last year or how far along they are, it will be different and [redacted] middle school has re-sequenced the math to align with the core.  Some of the skills are the same, but now it includes statistics and some more thinking-based processes instead of only computational-based standards so there will be new stuff not just for the kids but for the teachers too.  Since I have some pretty solid familiarity with the core from my work over the last couple of years in a national pilot with the math core, I decided it would be good to have my kids prepped a little so they won’t struggle as much with the changes and will be prepared to be more helpful to their peers and the teachers.

My girls were actually excited to do the math, but my son was less enthused so I had this really geeky idea that I would run him through a little math project aligned to the Common Core and see if anyone else is interested. It will be kind of a fun little project in which they look at graphs and charts to try to understand how statistics works and get their math brains going again since summer is always tough to recover from anyway.  I think my son would like it more if it were done in a group so… here is my
proposal for you:

*FREE SUPER FUN MATH PROJECT sessions in the Fleming’s Fancy Basement

– I will do two 90 minutes sessions, one for each of the next two Saturdays from 9:30-11:00 (August 11th and 18th)
– You can send your kid(s) to one or both of the sessions
– I am going to collect a $5 deposit upon entrance that I will *return *to the kids at the end of the session if they either master the math principles of the session or if they can prove they tried.  That way you and I both know that they got something out of it and if they don’t care, I get 5 bucks for my time and effort trying to keep them interested.
*Not including deposit

As I was planning the course I decided on this standard for 8th grade:

Investigate patterns of association in bivariate data.

What the heck is this??  Why can’t they just say something like two variables?

So I thought if I were a teacher trying to get kids to understand multiple variables and scatter plots, I would like for kids to have some general literacy about what bivariate data looks like and what it means.  I also thought that the stats leading up to this standard (I checked out the lower grades too) included binomials, understanding population sampling, and general understanding of stats and graphs.   I also thought that it would be important for kids to understand what the data is NOT saying just as much as they should try to learn something from it.

So… I decided to pick a topic of interest to the kids and pose a question to investigate:

Part I:

Pose question of the day:

What is the relationship between video games and violent behavior?

I had the kids pose a hypothesis.

On these cool white boards I had cut at Lowe’s (2’x2’):

Part II: Walk around the room and look at data in conjunction with a series of statements:

1)      Video games have gotten more violent.  What makes this statement true or false?

2)      Video games have caused an increase in violent crime.  What makes this statement true or false?

  1. Girls who play video games have worse behavior than girls who do not.  What makes this true or false?

  1. Boys who play video games are more likely to have behavior problems than boys who do not.  What makes this statement true or false?

  1. As the use of video games has increased, so has bullying and teenage violence.  What makes this statement true or false?

I gave each student a color and for each statement they had to write what made the statement true or false.  I gave them a choice of pairing up or working alone and I had a mixture of both.  Some kids would write alone and then gravitate to another team.  Some wanted to work with a partner the whole time and some kids wanted to be alone the whole time, it seemed to be a good strategy.

As I was walking around, I found that the questions they had the hardest time with were the tables about violent behaviors for the gamers.  I had semi-anticipated this based on the fact that it was not only complicated but the question asked them about data that was NOT on the chart—the overall incidence rate of behaviors is listed, but it does not disaggregate non-gamers.  It was really interesting to hear the dialogue and it was also a great opportunity to demonstrate the value of a good graphical summary of data.

Part III Discuss findings

Once they came back together, we went through each of the boards and had them clarify any comments, explaining their proof from the data that their statements were accurate.

I also asked them if their original hypothesis had changed after looking at the data.  I was surprised how much the kids understood about the data but what was even more interesting was their interpretation of the data.  Many assumptions came up, but the two predominate conclusions that came up were:

  • Video games have caused a decrease in violence because kids can take out their violent aggression through games instead of people
  • M-rated games cause violence

Are video games the ONLY explanation for violence decreasing?  Are you sure?  Where does it tell you in the data that video games made a difference in violent crime?  What if we looked in a place in the world where there was no electricity and we noticed that violence was decreasing too—what would you say the cause would be there?

I asked them to then draw a picture of an experiment they could run to prove that video games really did decrease violence.  Each team struggled for a bit but then one team had drawn a picture of two houses:

Then another group chimed in with “but it would have to be 100 houses!” and then a third said “I think all the houses would have to be people who never played video games before and see if their violence changed.”

So we collectively talked about independence of variables.  Pretty cool, right?  I also had them define correlation vs. causation, I don’t honestly know if those are math standards but seemed relevant to the conversation.

Finally, I had them take the charts that they struggled with and asked them to draw a graphic representation.   This was super fascinating!  The one girl in the group,  younger than the other kids by two years, generated this chart.  She got the idea of key, x and y-axis, and did not hesitate to jump right in:

The boys, who up until this point had really understood the data even more than her, produced stuff like this:

And even that was only after looking at her work.

Finally, I had them leave with an exit ticket of explaining the difference between causation and correlation, and then giving them an assignment to look at a minimum of one chart or graph and decide what the graph IS saying vs. what it is NOT.    We have part II tomorrow morning, I hope they retained what we discussed last week!

— Lee


I feel like there’s a lot to learn here. What were your takeaways as an educator? Likes? Wonders? Clarifying questions? Next Steps? Let’s hear them in the comments! And thank you, Lee, for providing us a really nice case study.