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Archive for the ‘Engagement’ Category

I take no credit for this idea at all. I was in a classroom this morning, and the teacher had the students play a game of Radical SNAP. The students were totally engaged, and were enthusiastically converting between mixed and entire radicals. It’s pretty simple to set up.

Materials: You need one deck of cards with the 10, J, Q and K removed for each pair of students, and one giant square root symbol per pair of students. This one should do the trick: Giant Root

Pair off the students in your class. Each pair gets a deck of cards, and should remove the 10, J, Q and K. Shuffle the remaining cards, and deal them so that each person has half the deck, face down.

Mixed to Entire

The students flip over their top cards. The student on the left puts his in front of the radical, and the student on the right puts hers under the radical. The first student to correctly convert the mixed radical to an entire radical wins the round.

Photo 2-12-2014, 11 01 43 AM

Entire to Mixed

The students flip over their top cards, and put them both under the radical. The first student to correctly simplify the radical or to identify that it can’t be simplified wins the round.

Photo 2-12-2014, 11 11 48 AM

 

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Last week, I had the pleasure of attending a workshop with Peter Liljedahl from Simon Fraser University. The session was on assessment, but he opened with his take on problem solving. I’m going to discuss the assessment stuff in a later post, but I really wanted to talk about his problem solving process while it was fresh in my mind.

Peter grouped us randomly by having us select cards, and then gave us the following problem.

1001 pennies are lined up in a row. Every second penny is replaced with a nickel. Then every third coin (might be a penny or a nickel) is replaced with a dime. Then every fourth coin is replaced with a quarter. What is the total value of the coins in the row?

He gave each group a whiteboard marker, and a window or small whiteboard to work on. We were to solve the problem on the space we were given. Peter circulated and encouraged us to look at what was written on the other windows if we were stuck. In the end, most of us were satisfied that we were right. Peter never told us the answer or revealed it in any way.

Here’s what interested me about Peter’s take on problem solving, which is very similar to what I have advocated as Learning Through Problem Solving.

  1. The problem wasn’t written down any where. He just told us the story, clarified, and put us to work. This isn’t a textbook problem.
  2. He grouped us randomly, rather than letting us sit with the people we came with. Throughout the day, he kept on re-grouping us. His feeling is that this frequent changing of the groups leads to more productive classes, and helps include all students. Kids are more willing to work with someone they don’t like when they know that it won’t be for long. This process helps include even the shy and “outcast” students in the classes. These students are included because the people working with them know that the groups will change again very soon, and so they can be patient for that long. Peter also has a way to assess group processes, which I will discuss in the subsequent post on his assessment material.
  3. Writing on non-permanent surfaces is critical to Peter’s process. He has observed that when kids work on paper, they take a long time to start. When they work on something like a window or a whiteboard, they start right away, because they know they can erase any mistakes easily. Groups that are stuck can step back and see what the other groups are doing as a way to help them get started. When finished, each group’s work  is displayed prominently around the room so that students can share solutions with each other in a non-threatening way. Students could do a gallery walk and discuss the different solutions, or sit down and write down one that works for them individually.
  4. This is the third time I have had the pleasure of working with Peter. He has never once told us the right answer. This drives teachers nuts. I’ve tried it in classrooms, and it drives kids nuts. The message, though, is that they have to figure out the answer. The teacher isn’t going to let them off the hook. An even more important message is that the teacher is less concerned about the answer than she is about the process. These are two pretty nice messages.

Peter’s problem solving process fits really nicely with the Learning Through Problem Solving discussed frequently on this blog. There’s always a “yeah, but” when I share some of this with teachers. They have one whiteboard, no windows, and nothing else to write on in their classrooms. Let me solve that problem for you.

Superstore has $20 whiteboards that are just the right size. Staples has tons of different sizes available for less than $30 each. I’m confident you could get enough whiteboard space in your classroom for 15 groups to work for less than $300. Your principal will find that kind of money in a hurry, especially when you explain that you are going to use it to enhance mathematics instruction by engaging students in group processes that will lead to better problem solving skills. I’ll write you a letter if you need one.

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When I was in high school, I had a teacher who used something other than boring old “Name: __________” at the top of his tests.  He’d put things like, “Hello, my name is: _______” or “_____________ is going to ace this test.”

When I started teaching, I did the same thing.  The kids really liked it, and any time it left room for creativity, they did some neat stuff.  Over the years, I acquired a pretty long list of them.  Whenever I created a new test or handout, I would open up the document with all of them in it, and pick one.  Sometimes I asked students to write their own. There is nothing pedagogically brilliant about this.  It just amused me.

Here’s the document.

 

 

 

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October’s issue of the NCTM Mathematics Teacher magazine included an excerpt from an interesting article in their Media Clips section.  They used a Forbes article that dealt with tween earnings, and the portion they included is:

Hollywood’s 10 top-earning tweens collectively pulled down $107 million between June 1, 2007 and June 1, 2008.   According to Alloy Media and Marketing, it’s a rabid and often indulgent fan base: America’s 20 million kids aged 8 to 12 spend $51 billion of their own money annually and influence $150 billion more in spending by their doting parents. Tied for the top spot: Hannah Montana star Miley Cyrus and Harry Potter lead Daniel Radcliffe. The young talents each banked a cool $25 million in the last year.

I love this article for the questions it could elicit.  The problem with the Mathematics Teacher Magazine treatment of this is that it follows the article with 8 questions we are supposed to ask kids.  Teachers might see this, and defer to the questions provided, thereby missing a great opportunity.  I’d much rather show students the article, and have the kids decide what would be interesting to explore further.  There are lots of potential rate and ratio questions that could come from student exploration here.

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This is an activity a group of teachers I was working with fleshed out based on ideas on Mark Wahl’s website, and here.  This activity is appropriate for Math 10-3 (Measurement) and Math 10C (Measurement or Real Numbers).

Statues of human bodies that the ancient Greeks considered most “perfect” embodied many Golden Ratios. It turns out that the “perfect” human face also contains many Golden Ratios.  This task allows students to take measurements of an ancient statue, and check whether these measurements approach the Golden Ratio.  Then two celebrity photos are provided and the students check how beautiful the celebrities are based on these calculations.  Finally, students can use pictures of their own faces and GeoGebra to check how they match the Golden Ratio.

Part 1 Students perform the measurements on a photo of a statue, and calculate the ratios requested.  These measurements could be made by printing the picture and physically measuring, or by inserting the picture into GeoGebra and using the software to measure.

Part 2 Students complete the same measurements, either on a provided celebrity photo, or one of their own choice.

Part 3 Students then take their own picture and insert it into GeoGebra.  They can then measure, and check how closely the ratios in their own faces match the Golden Ratio.  Students who are not comfortable using their own pictures can choose other celebrities from the internet. (I didn’t teach Cameron Diaz, but her face is much more likely to be beautiful using this test than my own…)

The complete student package in Word format is available for download here.

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This morning, as I was making my toast and about to put peanut butter on it, I was reminded of something I did early in my career in a Math 31 (Calculus) class.  It was at least 15 years ago, and way before we had digital cameras or Dan Meyer, but I think it definitely qualified as a WCYDWT.

One morning in the early 1990s, I was having peanut butter and toast, and had gotten near the bottom of the jar.  While scooping peanut butter out, I got it all over the handle of the knife, my hand, and then of course, my pants.

It occurred to me that the jar really was taller and narrower than it should be, and in a rare moment where everything came together for me, I realized that the shape of the jar was probably significant and we just happened to be working on Maximization and Minimization problems in Math 31.  Since digital cameras hadn’t been invented yet, the only multi-media artifact I could take into my classroom was the jar itself.

So I took my jar of peanut butter into class, slammed it down on the table in front of the class, ranted for about 5 minutes about how mad I was at Mr. Kraft for getting peanut butter on my hand and pants, and then told the class that we wouldn’t be doing Calculus that day, because I had to write a complaint letter to Mr. Kraft.  I sat down at my desk, and pretended to write, and hoped.  It took a couple minutes, but then it happened.  One student said something like, “Mr. Scammell, there must be a reason it is made in that shape.”  Another jumped in with, “It’s probably the shape that uses the least material but still has 1 kg of peanut butter in it.”  Then they argued for a bit, and decided on their own to figure it all out.  They measured, calculated, argued some more, and then told me to write my letter, because you could hold 1 kg of peanut butter in a container that was wider and shorter so my hand wouldn’t get peanut butter on it.

Again, I pretended to write while I waited and hoped.  And then they extended.  One kid stopped the whole thing, and said that there must be a reason it was the shape it was.  He observed that the lid was thicker than the other plastic, and therefore must cost more.  They re-ran their calculations based on an estimate that the lid cost twice as much as the other plastic, and then concluded that the shape was logical if we assumed the lid cost more.  It’s too bad that this was all done years before the internet hit our schools, or perhaps we could have quickly researched further to find out costs and contact numbers for Kraft.

I tried the Peanut Butter Rant several more times over the years, with varying degrees of success.  Some classes got right to the one important question, while others took some prompting.

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Here’s a WCYDWT for Alberta’s Math 10-3 on Ratios and Rates.

This fish, a 60 pound sturgeon, was recently caught and released in a small self-contained pond on a golf course near the Red Deer River.  When local biologists heard about the catch, they decided to investigate.  They surmise he (or she) came into the pond when the river flooded five years ago, and then spent the next five years feeding happily on the stocked trout.  Since sturgeon are endangered, it was important to return him (or her) to the river, which they were able to do.

This story reminded me that about ten years ago, I was fortunate enough to be present when a team of biologists surveyed a cutthroat trout population on a remote mountain stream.  Biologists typically use a method called electroshock fishing to stun fish so they can be tagged and released. They had a boat with a generator on it and a long metal prod which they poked around in the water.  When the current got near enough to a fish, it would be momentarily stunned, and float to the surface.  The biologists then weighed, measured and tagged the fish before returning it to the stream.  Any fish that had been previously tagged had its number recorded and it was again weighed and measured.  It was a humbling experience to see that there were actually abundant numbers of fish in that stream, because I had been unable to catch any earlier that day with my fly rod, but I digress.

I have used the story of watching the biologists electroshock fish several times in my classes as a ratio problem and asked students determine the population of fish in that stream.  Sometimes I gave my students the number of fish tagged on the first day, and then the number of tagged fish caught on a second run of the same stretch of river later on.  Other times (and probably a better problem), I had my students design an experiment to predict the population of fish before providing them the actual numbers.

Red Deer Advocate story about the fisherman who first caught the fish

Red Deer Advocate story about the biologists capturing and releasing the fish back to the river

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Eric Mazur is a Harvard Physics professor.  I came across this video when somebody posted it on Dan Meyer’s blog in response to another person who was demanding data to prove that Dan’s methods would work.  Professor Mazur has data to prove the merit of his shift from being a lecture style instructor to an instructor who facilitates peer teaching.  Peer teaching is definitely a strategy we could employ in our revised curriculum in Alberta.  If a University Physics professor can facilitate learning without having to tell his students everything, then certainly a high school math teacher who wanted to teach for understanding could emulate this process.  This video is about 80 minutes long, but is worth the time if you can spare it.  For those who can’t, I’ve summarized the key points below.

The reason that Professor Mazur switched his style was because his students were not showing gains when he compared pre-test results to post-test results.  Despite going through an entire term of his lecture style physics class, students could not show a significant improvement in their understanding of basic physics.

His Key Messages:

  • Students who have recently learned something are better at explaining it to other students than a teacher who learned and mastered it years ago. It is difficult for a teacher who has mastery of a concept to be aware of the conceptual difficulties of the beginning learner.
  • Give students more responsibility for gathering information and make it our job to help them with assimilation.
  • You can’t learn Physics (or Math or anything) by watching someone else solve problems.  You wouldn’t learn to pay the  piano by watching someone else play.  You wouldn’t train for a marathon by watching other people run.  If you want to learn problem solving, you have to do the problems.
  • Better understanding leads to better problem solving.  The converse of this statement is not necessarily true.  Better problem solving does not necessarily indicate better understanding.
  • Education is no longer about information transfer.
  • He says that in his original methods he covered a lot, but the students didn’t retain much so the coverage was basically meaningless.  In his new method, he has relaxed the coverage a little bit, but increased the comprehension enormously.

The Peer Instruction Process

  • Students pre-read the lecture notes or text.
  • Class is then used for depth, rather than coverage.
  • Depth is attained through what he calls a concept test.

The Concept Test:

  1. A question is posed.
  2. The students think silently about the question for a minute or so and it must be completely silent in the class.
  3. Students answer individually and vote by show of hands or by SMART Response systems.
  4. Peer discussion.  Defend your answer.
  5. Revised group answer.
  6. Explanation

Then he will “lecture” for a couple of minutes, and repeat the process with his class.

Benefits of his process:

  • This process promotes active engagement.  “It is impossible to sleep through class, because every few minutes, your neighbor will start talking to you.”
  • He can continually assess where his students are.

Challenges:

  • Teachers have to find the right questions to ask in their classes.
  • Students will write on their evaluations that professor Mazur isn’t teaching them anything and that they have to learn everything themselves.

My take on all this:

I see this process as being one we could employ in our high school classes.  I don’t think we’d expect kids to pre-read sections of the textbook, but we could certainly present problems to them in this manner and allow them to explore and construct solutions without having to tell them so much.

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For your viewing pleasure, here are what I believe to be all the entries in the binomial expansion contest.  They are presented without bias, and in no particular order other than putting the best one at the end.

Eric’s

James Tanton’s Part 1

James Tanton’s Part 2

Jason Dyer’s

Mine

Edit (May 30):  Jason Dyer’s was judged the winner in the competition.  See here for the rationale for the decision.  Congratulations, Jason.

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A few weeks ago, Kate Nowak posted on her blog that she was frustrated at the lack of online resources to support the teaching of the binomial expansion.  She threw out a challenge asking people to create a better way to teach the binomial expansion.

Here’s her challenge:

“Objective : Present the binomial expansion in a way that makes sense. Bonus points if students are able to as a result completely expand a power of a binomial and find a specific term in an expansion.”

Our revised curriculum in Alberta includes a pedagogical shift that asks teachers to create opportunities for students to establish their own meaning through exploration, problem solving, investigation and developing personal strategies.  One of the common concerns I hear from teachers is that we can’t teach higher level mathematics this way, because the material is so hard that students won’t be able to construct their own meaning.

Kate’s challenge gave me an opportunity to try to teach in this manner in one of our academic courses.  In Alberta, binomial expansion shows up in a pre-calculus course called Math 30 Pure.  Students go from that course into Math 31, which is a calculus course covering limits, derivatives, application of derivatives, and basic integration.  Binomial expansion, and the binomial theorem are two pretty dry topics.  I took the challenge and attempted to create a lesson that was both engaging, and allowed students to construct their own meaning through looking at patterns.  A colleague was nice enough to let me try the lesson in his class.

My lesson went over fairly well with the students, and I think I met all of Kate’s objectives.  The introduction/hook was more compelling than anything I had done in the past on that topic.  Students were able develop the patterns in the binomial expansion on their own, and were able to apply those patterns to expand more complicated binomials.  What surprised me was that they were able to come up with the formula to find any term in an expansion all on their own.

I’d love to hear some feedback on the lesson.

An 11 minute compressed version of the lesson can be watched here:  Binomial Expansion Lesson

If you’d prefer to just read the lesson plan, here it is.

Lesson Plan

Introduction:  I showed them a mathemagician video from TED.

Hook:  I claimed that I was a mathemagician, too. I wrote (a + b)^2 on the board, and asked them to expand it. Then I wrote (a + b)^3 on the board and had them expand it. Then I wrote (a + b)^4 and (a + b)^5 and challenged them to a race. They could use friends, pencil, paper, calculators or whatever they wanted, and I would just use my brain. I pretended to struggle, and then wrote down the answers as quickly as I could. I had to hurry because one kid was darn quick, and was getting at (a + b)^4 by multiplying the answer to (a + b)^3 by (a + b) rather than expanding the whole thing as I had expected them to do.  If you watch the video, we appear to tie on that one, but he already started while I was blabbering.

Students look for patterns:  I explained that I am not really that smart, and that I was cheating using a pattern. I wrote “In the expansion of (a + b)^n, ” on the board, and asked them to spend a few minutes together coming up with ways to complete that statement. They got that each term had the same degree as the exponent on the binomial, and that there were n+1 terms in the expansion. It took a little longer and some direction from me for them to notice that the a’s started at a^n and decreased to a^0, while the b’s did the same thing in the opposite direction. One girl put Pascal’s triangle on the board when she noticed the pattern of coefficients.

Expand a binomial:   I asked them to use all that they had learned to expand (x + 2y)^5. They worked together and there was much discussion about how to handle the 2y part. They managed to figure it out.

Develop a formula for a general term:  I gave them one like (x + 2y)^12 and asked them if they could figure out the 8th term without writing out the first 7. I gave them three blanks to fill in: coefficient, “a”, and “b”. They got the a and b part just fine, but struggled with whether the coefficient should be 12 choose 7 or 12 choose 8. They figured it out by counting.   I told them that they had just figured out the formula. I wrote the formula tk+1 = nCk x^(n-k) y^k on the board.

(At this point I fell back into my old bad lecture style, and did two examples with them using the formula, rather than making them do it themselves.)

Example: Find the term containing y^7 in the expansion of (x – 3y)^7.

Example: Find the constant term in the expansion of (3x – 2/x^5)^12.

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