After another round of conversation on twitter that included tips from a student who just graduated from our school, I have been playing with three different data sets. I want to play with average daily temperature, high tide level, and with daylight hours. The data for the first two came from wunderground and the third data set came from dateandtime. Below are pictures of the data and Desmos links to the tables.

This picture (above) shows the average daily temperature in my town during 2017 at 10 day increments. You can see the Desmos table here. There are some things I like about this picture. I like the fact that the general shape can be inferred. We can talk about why it fluctuates on a number of different levels. However, I don’t think that this is a great data set for beginning to develop an idea of periodic functions. It feels too noisy to me.

Here is the picture for high tides.

This table was built on data at 6 day intervals from the beginning of the year through June/July. You can see the Desmos link here. I would definitely ask the students to play with window sizing and I think that some powerful ideas about amplitude and vertical shift can quickly come out of such a conversation. I picked 6 day increments thinking that I would be slightly off phase with what I thought would be a period related to the full moon. A quick survey on google just talks about a 12 hour plus period so I may have been making this up in my mind. This picture feels more friendly with just a little noise involved. I might use this one early – maybe even on day one. The next one is much cleaner looking. Here is the data on length of daylight hours during 2017.

This is where my mind was when I created the demo lesson. However, this data is for our hometown here. You can see the Desmos link here. My thoughts about this data set go down two different paths. One thought is that this is clean and clear and easily explainable. One tweak I might make based on my conversation with Bonnie is that I might extend past one full year (say about 400 days or so) to make the periodicity visible not only intuitively meaningful. My second thought is that this might be too clean that it might lead my students into expecting such clean, clear periodicity in a messy world. I am probably overthinking this on the second train of thought.

I expect to have five table groups of students (groups of three in my classroom after long debating it, I accepted the wisdom shared by a number of MTBoS folks – especially Alex Overwijk (@AlexOverwijk) and my classes were better this year because of that change!) and I am thinking that each table group should have different data. I am playing with the idea of mixing up sunlight or tidal subsets of data versus simply subdividing one larger set. For example, if I go with the cleaner daylight data I can extend it to about 450 days or so and give different table groups subsets of about 35 data points each. I feel that they would benefit from seeing how the data ‘fits together’ and that individual table group decisions about amplitude, vertical shift, and period all match each other pretty well.

I would love some feedback/suggestions/questions and I thank Bonnie again for her valuable thoughts. You can drop comments here or over on twitter where I am @mrdardy

## It’s Not Just a Dream – The Reality of a Data Project

Right now my AP Calculus BC class is taking their final test of the term. I hope I am as happy grading those as I am thinking about my AP Statistics team right now.

## Wrestling with the Modern World

If the answers to my tests can be looked up on Google, are they really worth asking in the first place?

I want my students to be creating, to be evaluating, to be synthesizing information.  I want them forming opinions and interpreting answers.  It would be great if they could determine the circumference of a circle from it’s diameter.

It would be better if they could tell me which of the given answers is the most reasonable estimate.

A smart phone can’t make judgement calls.  They can’t interpret answers.

If a smart phone can answer my test questions, I’m asking the wrong questions.

I agree 100% with these sentiments. When I first visited my current school I saw a chapel presentation that completely won me over. It was one of the 4 or 5 major reasons why I am here. Our  Reverend addressed these ideas and won me over. I do not think that this is the real reason why I worry about cell phones or other connectivity issues on assessments or in my class. Justin writes passionately about students doing what he wants (needs?) them to do while still being connected electronically through their phones or their headphones. What troubles me is a persistent belief that I have that we all benefit when everyone is engaged in class. The student who is doing solid math while wearing headphones is depriving their classmates of a strong voice and they are depriving themselves of the opportunity to explain their own thinking or to hear the thoughts of their classmates. I believe SO strongly that learning ought to be social and interactive. Maybe I am just inflating any logical concerns about relating to each other but that is where my heart and my head are right now. I don’t know how to balance what I want, what my students want, what I believe is best for the group as a whole, and the needs of the individuals. I know that there is a sweet spot there and that it almost certainly varies by class – hell, even by time of day.

I have asked my students to have their phones on their desks this year. We know that they are in the classroom and I don’t want surreptitious use in their laps. I ask them to look up stuff, I recognize that some of them use their phone as a rudimentary calculator. I don’t pretend that these don’t exist and I want to encourage honesty and openness about their presence in the classroom. Some students have complied while others have not. I speak patiently (but consistently) with those who keep them in their laps and text friends during class.

I know that I want my students to interact and I believe that they do less of it when they are plugged in to their phone or their headphones. I want students to research and solve challenging problems and I know that they do less of that when they are not connected to the internet through their phones or tablets or laptops. I chaired a committee at our school that helped develop a 1 – 1 program in our middle school. That program should soon bubble up to our high school. I believe in technology. I do, I think it improves learning and depend understanding. I am jealous of my students when I get to display complex ideas with Desmos or GeoGebra because I am old and did not even have rudimentary graphing technology available when I was trying to learn trig and calculus. I cannot tell if my visceral reactions to cell phones is at all logical and I am trying to sort that out. Justin – thanks for making me think and making me uncomfortable. Anyone else out there reading this – please poke at me through comments or through twitter (I am @mrdardy) I want to sort through these conflicts. I want to create an environment that is meaningful for my students AND for me. I sometimes feel like the grumpy old man yelling at kids on the lawn (even though I don’t have my own yard!) even though I don’t want to believe that is me.

sigh… This stuff is hard.

I used this conversation with a number of goals in mind. I want them to get in the habit of talking to each other. I want them to see that there is not just ONE way to do math problems – especially ones as sophisticated as the ones we talk about in BC Calculus. I want them to think about graphs. I want them to utilize resources such as Wolfram Alpha, GeoGebra, and Desmos. I want them to notice and wonder about relationships. They are not yet where I want them to be in these terms, but the more often I remind them and the more often I model this behavior, then the more likely they are to adopt these behaviors.

If I did not believe this, I might not have the energy to keep on keeping on in this job. But I do believe it and I do keep on keeping on.

Thank you world of math resources for my students! Thank you world of recourses for me!!

## Changes for the New Year

So, I had recently blogged about some ideas to change the pace of my Calc BC class and I want to report on how it is going so far. We are one (partial) week into the new year. We lost Tuesday to extreme cold and I am losing the second of my two BC classes today because I’ll be visiting another classroom. As department chair, it is one of my obligations (and one of my real pleasures) to visit my colleagues to watch them at work.

I have two very different sections of BC this year. My morning class has seven students and they are somewhat reluctant to work together. They get along fine, they are just much more independent workers by nature. My afternoon class has seventeen students and they are much more social and collaborative.

I want to summarize the past two days by section, rather than by day.

Yesterday, my afternoon class also met in the computer lab to work with Desmos. Again, I spent about three to five minutes looking at an animated drawing of the polar curves I mentioned above. For the next thirty minutes the class had a consistent hum of chatter, people arguing with each other about conclusions, kids looking at each other’s work. When I reconvened the class to focus on the same k = -2 case, they were engaged. telling me what the hyperbola equation was, catching a mistake I made in factoring, just a lively discussion. When class ended, I checked in with two students who were just packing up. One of them said something to the effect that my class made his head hurt a bit. He said it cheerfully and his neighbor said that my class was ‘interesting’ which is the word I use to describe difficult or challenging questions. He, too, said this rather cheerfully. I won’t be around to see them work on the problem sheet but I have asked the colleague who is subbing for me to collect their work so I can see what they can accomplish and how they approached these problems.

Now, I am left with these questions as I move forward.

1. How do I create a situation so that my first period class actually talks to each other?
2. Is it important enough to make that happen, given that they are productive workers? I have a pretty strong belief that talking about ideas is important, but I don’t know how to win this class over to that point of view. Is my personal bias important enough to try to change the nature of my learners in my 1st period class?
3. Can I build momentum for these problem solving days if they only happen once per week?

I’ll keep reporting on progress and I’ll keep an eye on any wisdom that you can share int he comments section.

## Brrr…

So, today we saw school cancelled due to the cold weather here. Woke up to an air temp below zero and wind chill about 20 below. Took the morning to finish the first of my weekly problem day assignments. I’m sticking to my guns and using this Thursday as our first class work day despite losing today to the weather. I sent out a parametric/polar practice sheet to my kids and asked them to spend some time with Desmos. Tomorrow we’ll be in the computer lab working with Desmos (gotta get started on that doc next) and then we’ll have our problem day. I’ll report back on how it goes. The doc I created that is linked above is a collection of stuff I’ve scoured from the web.

## Parametrics / Conics

As I have written before, we teach AP Calculus BC here as a second year Calculus course in our school. This gives me loads of time to play and explore with these students. On Monday we start up again – weather permitting – and we start with our study of parametric and polar equations. Our precalculus class does not cover either topic in great depth (a situation I hope that I can remedy starting next year) and a number of our BC kids are ones who start off in AB Calculus when they come to our school. With so many of our students coming from different parts of the world at different times in their career, we have a wide variety of experiences in the BC group. I guess this is a long-winded way of saying that I have to treat this material as if they have not encountered these ideas at all, really. I intend to spend two days in our computer lab working with building up some fluency with Desmos. I have my room set up in a sort of Harkness-style where the kids are facing each other. Being in the computer lab gives me the flexibility of having the students work with Desmos in a hands-on fashion rather than just watching me. That’s the plus. The downside is that they are working in isolation in this room. I’ll have to deal with that downside for a few days. So, I was digging through my memory bank and I remembered that the great Sam Shah had written a lovely post about introducing conics through Desmos. I downloaded his Scribd file and modified it a bit (you can see my version here) but I still need to go back and play with it a bit more. The way the file looks to me now is way too close to plagiarism – though I do give his website a nod of thanks there. I want the language and the feel to reflect my language and the way my students react.

I am making a real commitment to myself to get out of the way more in 2014. There was a lovely piece that was tweeted out by an old colleague named Gayle Allen. It was called ‘Becoming Invisible in My Classroom‘ and it has given me a renewed sense of mission here. I am also thinking of my visit to SLA last year for EduCon. I walked into a physics class and could not figure out who/where the teacher was for a few minutes. I was amazed and humbled. Need to hold on to that feeling…

So, I’ll start on Monday with a bit of leading/lecturing to set the stage. I’ll give them an assignment to play a bit with Desmos Monday night, then we hit the lab. I’ll be giving an update on how it goes. Wish me luck!

PS – I have a fun Desmos file to look at for them as well. You can see it here. It’s fun to animate the slide and see what happens.

## MTBos Mission #3 – Daily Desmos

So, the challenge this week was to pick a collaborative site and … collaborate! So, I chose DailyDesmos for a number of reasons. Years ago, when I was a student again for a glorious time, I fell in love with GeoGebra. For the past few years I have been preaching to my students and colleagues about the wonders of GeoGebra. I reached out to a colleague from Lawrenceville and had him come out and do a workshop for my school teammates. Fun has been had with GeoGebra. Recently, I was introduced through the wonderful blogger world to Desmos and I am in the process of falling in love with it as well. Recently, with my precalc honors class we had a triumph using Desmos. I blogged about it on Sept 10 and included this link ( https://www.desmos.com/calculator/nvinc8pwdh ) when my kiddos wrestled with creating a trig function to match the daily average temps of my old, beloved hometown of Gainesville, FL. This morning I dove in and took on challenge 201a ( http://dailydesmos.com/2013/09/23/daily-desmos-201a-advanced/ ) which was presented by the awesome Michael Fenton. Here is my crack at a solution to that one ( https://www.desmos.com/calculator/zmuvzpmvti ) and it is probably not as dynamic as it could be. I still need to learn about leaving traces behind rather than simply having the slider generated graph be new at each stage. I am imagining a sort of spirograph and I am certain that Desmos can handle that. I still love my GeoGebra – especially for individually rescaling axes as I go – but I am finding room in my heart for Desmos as well. As my school inches toward greater tech integration, I am seeing a day where my students would be spending time in class (on their own or in their pods) where they are tackling these daily challenges now and again. I am also dreaming of a time when I feel that I have time and energy on a regular basis to tackle these challenges.

I have thoughts about these graphs that I need to organize and make coherent. Another post for another day.