# Posts

### May 23, 2015

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12:21 AM | Mapping Out a Course

A correspondent writes (I added the links):Our district is looking at revamping our year map and I would like to suggest a map that has the qualities of Algebra: Themes, Tools, Concepts (ATTC): particularly its ‘integratedness’ and how well it spirals through the topics. I’ve read on your blog about separating topics and lagging homework. But what are some things one might consider when deciding what the next week’s topic would be (or what topics to put in what
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### May 22, 2015

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11:00 PM | On This Day in Math - May 23

(a symbol) We can repudiate completely and which we can abandon without regret because one does not know what this pretended sign signifies nor what sense one ought to attribute to it. Cauchy in 1847 in regard to the square root of negative one..The 143rd day of the year; there are 143 three-digit primes. Also, 1432 is a divisor of 143143. HT to Matt McIrvin who found the pattern for numbers such that n^2 divides n.n (where the dot represents concatenation) and then […]

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10:25 PM | Would appreciate any help on this problem

We are in the middle of moving and I just for now don’t have access to my compute that has Mathematica. I hadn’t really worried too much about it since we really only use it for 3D printing projects, but guess what . . . I was reading through this book in the library today:…

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Unizor - Creative Minds through Art of Mathematics - Math4TeensProblemConstruct a common perpendicular h to two given skew lines a and b.AnalysisAssume a common perpendicular h to skew lines a and b is constructed. Let points of its intersection with these lines be A and B correspondingly. Then h must be an intersection of two planes: plane σ that is perpendicular to line a at point A and plane τ that is perpendicular to line b at point B:σ⊥a; A∈στ⊥b; B∈τh = σ∩τWe don't know […]

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6:54 PM | testing

\[\begin{array}{c}345 - 158 = 345 - 100 - 50 - 8\\ = 245 - 50 - 8\\ = 245 - 45 - 5 - 8\\ = 200 - 5 - 8\\ = 195 - 8\\ = 187\end{array}\] \[\begin{array}{c}345 - 158 = 245 - 58\\ = 195 - 8\\ = 187\end{array}\]Why do both look correct on PC but only one on iPhone?

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6:00 PM | What Made This Semester Awesome

This semester had, hands-down, the best set of students I’ve ever had. Every semester I do a post-mortem of what worked and what didn’t and how consistent those things have been over the years. Though, mostly irrelevant to this article, but to give a frame of reference, this semester I taught a once-a-week low-level, introductory […]

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5:53 PM | disentangling the dilemma

Wow! I was going to write a comment synthesizing the very generous thoughts and ideas in response to my last post, but the meta-comment got to be almost as long as the original post, so... here I am. Several categories of possible actions jump out to me:Representing the incorrect idea: By not putting this idea on the board, I'm subtly signaling that it's wrong, or in some way not worth recording. This occurred to me-- which is why I attempted to record the idea of a unit rate by writing 1 hour
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This lesson will extend the concept of selections and, in particular, will talk about the number of ways to select any number of objects from ‘n’ distinct objects. Let’s go back to color mixing! Suppose you have the following three colors with you: And you wish to make as many different colors as possible by […]

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I’ve been on both sides of this conversation. And this discussion can get heated. Do we tell students what we want them to know? Do we let them explore? Do we let the students develop their own understanding? Do we model proper techniques for the students? And this isn’t a particularly new debate. John Dewey […]

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5:10 PM | Viral Math, Part Deux

Viral Math, Part Deux: Terrance F. Ross:Singapore’s mind-bending logical riddles are so last month. Enter: Vietnam, the latest country to be swept up in what could easily be known as “the viral-math epidemic of 2015.”

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5:04 PM | KrazyDad.com

KrazyDad is a website choc full of mathematics based puzzles Many of these were featured in my blog post about maths puzzles a few months ago.

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4:51 PM | Our 2014-2015 Issue of Intersections

Another teacher and I started a math-science journal at my school three years ago. We’ve built it up to the point where it is very student-run, and we teachers truly are advisers. Today we had our launch event for the journal, and it is the current issue is now “live.” I’m so proud of the kids […]

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4:30 PM | OAME 2015: Rethinking Math Class

Last Thursday, at the OAME 2015 math conference, I presented a double-session entitled Rethinking Math Class. I am going to try to recap it here, as best I can, with links to everything! So expect this to be a long post...First, we played Quadratic Headbanz, which I have blogged about here. Given that 64 people had signed up for my session I had to make a second set of headbanz. As my original set featured equations I decided to make the second set with graphs which you can get here. As it
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4:00 PM | Street Photography: Seven Photos

Seven cities, seven photographs, seven skilled photographers! Join me on a whirlwind world street photography tour.

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3:12 PM | Dumbed down markschemes?

Today I was working through the June 2014 Edexcel M1 paper for my year 13s, noting down thought processes etc and I arrived at this question: It’s quite a nice, general bouncing ball question that takes into account many of the rules of mechanics. When I finished the question I checked it against the markscheme […]

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2:43 PM | MFM2P - Day 70: More Trig

I had to take two of my kids to a doctor's appointment this morning so a colleague was kind enough to cover my class. They started with this warm up:And this is where they went with it:Then they worked on the trig matching some more. They also talked about the steps involved in solving a trig word problem and did one example together.We will on to quadratics on Monday.

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2:36 PM | Two Nice Things: A Gift!

I've talked about my two nice things rule before and mostly because it's the one thing I've been consistent on throughout my entire teaching career.When someone says a rude or mean comment about someone (whether they are in the room or not, or a family member, or celebrity, or someone I've never heard of) they must immediately say two nice things about that same person.It's not about the nice things really being meaningful but it's about being consistent and sending a reminder that words […]

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2:02 PM | Iowa BIG is Change Today

I’m going to see Seth Godin speak this afternoon at Iowa City’s Entrefest, and I have to admit that I feel inspired to be a change agent today; it’s been hard to maintain that lately. Running Iowa BIG has sapped nearly every ounce of energy I’ve been able to cleave from Lucky Charms and coffee... Continue Reading

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Click the flyer to download full Administrator Academy details When: June 16-17, 2015 | 8:00am-9:00pmWhere: John E. Fetzer Center, 2350 Business Court, Kalamazoo, MIRegistration Fee: Consortium: $250 | Non-Consortium: $400 (Fee includes light breakfast, lunch and dinner both days)Credits: 50 SCECHs or
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This post is more a reminder for me the next time I teach trig than anything else. I'm teaching statistics again next year, by the way. And, I'm doing INBs with my students instead of using the textbook like my first go at teaching stats. I'm super duper excited. Also, I'm going to have more than 5 kiddos which means we can do data collection activities that result in enough meaningful data to analyze without bugging other classes! Okay. Back to trig. […]

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Traveling this morning, but would have loved to have been able to ask the boys some notice / wonder and same / different questions about these two things this morning: First Dan Anderson’s amazing geometry video / program: Second, the famous bowling ball pendulum:

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11:02 AM | Groups and Group Actions: Lecture 16

In which we meet Cayley’s Theorem and reach the end of this particular adventure, but catch a glimpse of far-off lands still to be explored. Theorem 68: Let be a group, let be a set. Given a left action of on , there is an associated homomorphism . Given a homomorphism , there is an associated […]

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“Life can only be understood backwards; but it must be lived forwards.”― Søren Kierkegaard++++Lots of students have observed that they didn't really understand a subject until they_____algebra calculus++++++++++++++We need A to prove B but we need B to understand the why of A.+++++++++++++On the first pass, jettison all of the inessentials from A

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8:02 AM | Reaction Time & Web Data Collection

If you put out an open call through email to complete a task for nothing in return, it might make sense not to expect much. I tried to make it as simple as possible to gather some reaction time data … Continue reading →

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2:25 AM | Maintaining Sanity, Reviewing Priorities

I've had a really busy year. I've always said at the start of the school year that I'm going to say 'no' more frequently in as politely a way as possible. I've said I'd be more honest about priorities. Instead … Continue reading →

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12:09 AM | Listening Carefully to Student Thinking

Recently, I have been reviewing a new “CCSS-Aligned” middle school curriculum and find myself completely frustrated with the overabundance of scaffolding and lack of student thinking required on every assignment. Not having the days/weeks it would take for teachers to engage in the mathematics as both learners and teachers, I needed a short, powerful way […]

### May 21, 2015

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11:47 PM | Schooltoon: La Scuola A Cartoon

Cosa è Schooltoon? Ve ne accennai l'anno scorso nel post "Le proporzioni...E Lo Scherzo A Ferrari", ma ho deciso di dedicare un post specifico a questo progetto interessante, che nel frattempo è cresciuto.Riporto di seguito la presentazione che ne fa il sito dedicato al progetto:"Schooltoon è una ‘scuola a cartoon’, nella quale il Prof. Eddie, Moretti, Giovanna e tanti altri personaggi rivoluzionano il modo di insegnare ed imparare, attraversando a suon di rock i
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11:00 PM | On This Day in Math - May 22

The Le Petit Journal cover, on 1912 April 21, shows eclipse watchers in 1912 along with the solar eclipse of May 22, 1724, the previous total solar eclipse visible from Paris, France“Biographical history, as taught in our public schools, is still largely a history of boneheads:ridiculous kings and queens, paranoid political leaders, compulsive voyagers, ignorant generals - the flotsam and jetsam of historical currents. The men who radically altered history, the great scientists
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10:43 PM | Bingo Lingo

This time of year, the standards used to measure the success of a lesson may look different than they do at other times of the year. For example, some teachers might consider “Students not using worksheets to have paper airplane throwing contest” to consistute a lesson well executed. To a certain extent, I am joking, […]

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10:30 PM | ICPC 2015 World Final Problem D

This is a solution to problem D from the International Collegiate Programming Contest. The list of the problems can be found here. This is one of the problems which was really appealing for me, from the start. The idea is the following: suppose you have a Swiss cheese cube of (the units are centimeters). This […]