Category: series

Total 134 Posts

WCYDWT: Polynomials

Ha ha. J/k. There isn’t a picture for polynomials. That’s insane. The question about polynomials comes up, though, especially when we give into the fiction that students can’t enjoy math for its own sake.

Let me highlight two positive externalities of WCYDWT, which is to say, benefits of WCYDWT that don’t limit themselves to the time that we are actually WCYDWT-ing:

  1. The class understands that non-standard approaches are awesome.
  2. The class understands that failure is useful, not shameful.

You can capture those benefits using traditional curriculum but you have to work a lot harder at it and if you stop working harder, you capture the negative externalities: students come to understand that math is a right or wrong endeavor in which “wrong” is an destination unto itself rather than just another waystation to “right.”

The last two years of my career I facilitated classes that were often fearless and creative. That meant this: if they were really confident with trinomials like x2 + 7x + 6, I didn’t have to lecture. I’d just write on the board: 2x2 + 7x + 6.

Which would offend them. You know, like, “how dare you bring that weak stuff in here, Meyer? You didn’t see what we just did to the last trinomials?”

Because they were creative and because failure had little stigma attached to it, students would start putting answers down. They’d experiment. In math. Worst case, maybe one of them would throw down (2x + 7)(x + 6) โ€“ just banging the numbers from the question together, hoping to see some sparks. She’d call me over and ask if it was correct. I’d tell her to check it. “You know how to multiply binomials.”

She’d see she missed it โ€“ 2x2 + 19x + 42 โ€“ but we’d notice she nailed the 2x2 โ€“ “keep that!” โ€“ and ask her to experiment some more. My role in class was to help condense and summarize the findings of student experimentation.

This is how you maintain the spirit of WCYDWT even for concepts that seem to defy the spirit of WCYDWT.

WCYDWT: Burning Man

Click the image for full size. You have to see it full size.

1. What questions perplex you about this photo?

What’s the perplexity score here?

davidwees: How many people there?
Peter: how many people are there?
Roz: How many people?
schwartz: is it bad that i want to know the area of the shaded regoin?
JG: How many rows can be added until the circle touches the pentagon?
Colin (@ColinTGraham): How was it built and measured out?
Sam Critchlow: what/why is the gap between the pentagon and the circle
JG: How much area is added on with each additional concentric circle?
Sam Critchlow: or what is the total open space area
Chris: how many more people to complete the circle?
Colin (@ColinTGraham): what’s the significance of the pentagon
Nick Hussain: how many more people/dwellings (?) could be added if the circle was completed?
JSR: what’s at the center?
Colin (@ColinTGraham): how many sectors if the circle was complete

We went with:

davidwees: How many people are there?

2. What is your guess? What is a number you know is too high / too low?

3. What information would you need to answer the question?

JG: Average number of people in each rectangular region
schwartz: people per square something
davidwees: I think we can estimate people per square
schwartz: radius of part circle?
Barb: Was admission charged? If so, who sold the tickets? They could give a ballpark figure
Colin (@ColinTGraham): is each sector evenly divided and how many sit in each of the eleven concentric rings?
davidwees: and get the scale from the size of the tracks shown
Roz: we definitely need scale

David’s response is right on point:

davidwees: so I think we could get a pretty good estimate without much more information

You don’t need anything more here. (I wonder what it takes to get students comfortable with imaginary units, as in “the radius of the circle is 500 burningmans,” etc.)

Nevertheless, here are two images that are interesting, if not useful also:

4. Submit your work.

I knew we wouldn’t have time for this. Here’s the Evernote page, though, where Colin Graham posted his work:

5. Show the answer.

[BTW: Though the photo is clearly timestamped 2009, various commenters have outed themselves as serious Burning Man attendees to tell me that this is 2010’s photo. I have adjusted the news clipping accordingly.]

Download High Quality

WCYDWT: Book Of Eli

Huge spoilers for the movie Book of Eli. You were warned.

Click through to view embedded content.

1. What questions perplex you about this video?

If we were assigning a score for perplexity, can we agree that this would receive a much higher score than Big Baby?

Jazo: how long will it take for him to recite the whole bible?
Sam Critchlow: how long is this movie going to be if he speaks this slowly for the whole bible?
Peter: how long would it take to dictate the entire bible
Roz: How long would it take to transcribe the bible
Matt: how long to recite?
Chris: Given that the Bible was being recalled from memory and transcribed at the same time, how long might it take?

I set the units to “days” โ€“ I wouldn’t have done this in class โ€“ which led to:

2. What is your guess? What is a number you know is too high / too low?

3. What information do you need to answer that question?

Sam Critchlow: # words in bible
Chris: How many verses? Time per verse?
Peter: how many words per minute is he speaking? how many words in the bible
Roz: Are they taking breaks?
Jazo: how many words does he speak in a day at that speed?
schwartz: How fast a reader is he? How much time a day does he spend reading?
Matt: how many verses in the bible and average word length of each verse
Barb: I need to know if he reads 24 hours a day or takes breaks
Barb: Which version of the Bible
schwartz: How long is the bible in pages or words?

Three things about this conversation.

  1. It’s fun.
  2. It’s challenging.
  3. It doesn’t happen when you assign problems one through thirty odd.

I laid a timer over the relevant part of the video and linked it up, but you don’t even really need that. You’re counting. You’re Googling. (It’s the English Standard Version translation.) You’re calculating.

4. Submit your work.

Technical innovation: a public Evernote notebook.

Participants e-mailed my Evernote address with “@BookOfEli” in the subject. They attached a scan or a photo of their work and then everyone could see everybody else’s work.

5. Show the answer.

Technical demerits.

Download High Quality

WCYDWT: Big Baby

via Joshua Sloat, who offers up what is (I believe) our site’s first WCYDWT for upper elementary math students.

1. What questions perplex you about this photo?

Almost nothing went well here, which is what makes this particular moment so valuable for me. The image didn’t urge the question I thought it did, especially when I couldn’t easily clarify its meaning.

Sam Critchlow: how many players on a football team, are football babies bigger?
Chris: How many babies?
Matt: What do the yards and pounds represent?
Peter: what is 24,414 pounds? what is 7908 inches?

The intended question was:

Jazo: how many players?

I have no problem, in these situations, just asking the intended question, but I remind myself to tune my WCYDWT antenna to scan for a better provocation than this one.

2. What is your guess? What is a number you know is too high / too low?

Technical innovation: Google Forms to submit a) the guess and b) the upper / lower bound.

However you handle this, you’d rather not have one student’s developing number sense stunted by another student’s guess. Seriously. When I do this in class, everyone tracks within a standard deviation or two from the first guess, no matter how insane that first guess is. When JB says “the Eiffel Tower is 7 miles tall,” the next guess from AJ is “5 miles.”

3. How can you use math to tell if you’re right or not?

Peter: to know if your guess is right, divide total pounds by your guess

4. Play around. Decide if your guess was too high or too low.

We divided the total pounds (24,214) by one guess of 200 players.

Jazo: 121 pounds? sounds like a weak team
schwartz: less people!

5. Show the answer.

Download High Quality