I was a public school teacher in New York City for over 16 years. Then I taught mathematics at an international school in Frankfurt am Main, Germany. Now I'm mostly retired but still teach a few class each year at Purchase College. This blog is intended as a spot for me to record some of my observations.
Wednesday, October 20, 2021
Vietnamese Food in München
Tuesday, October 19, 2021
Hohenschwangau
Monday, September 6, 2021
Palindromic Depth
I tried a problem today in three classes, two 9th grade and on 7th grade, which I consider successful. I found the problem from Alicia Burdess (aliciaburdess.com) in a collection called Teaching Through Problem Solving. Also credited are Daniel Student, Geri Ann Lafleur, Dawn Morris Blackburn, Doris Duret, and Jonathan Scott.
The basic setup involves talking about number palindromes. I get into that with sentence palindromes, and my current favorite (which I first heard from my son) is, "No sir! Away! A papaya war is on!" I stretched this part more with the 7th graders, but eventually get into number palindromes, and then introduce an idea called palindrome depth.
If you take a number like 84, which clearly is not a palindrome and reverse the digits you get 48.
Add the two, 84 + 48 = 132, which is still not a palindrome. Reverse the digits and add again.
132 + 231 = 363, a palindrome.
Because it took us two operations to get a palindrome, we say that 84 has a palindrome depth of 2. Some numbers, like multiples of 11, have a depth of 0.
The task: find the palindrome depth of all two-digit numbers.
It was great that all students are able to access the problem. I definitely consider it low threshold. Students of all levels were excitedly exploring. I use visibly random groupings of three, and almost all groups were dividing labor and sharing results, and both making and testing conjectures.
One of the most interesting extensions a student with colored pencils came up with was to make a 9 x 10 table with each two-digit number, and they color-coded each number palindrome depth. Wow!
I will definitely use this one again.
Saturday, August 21, 2021
Thinking Classroom Links
In attempting to implement Thinking Classroom recommendations, I regularly run across ideas in twitter and (less often) in facebook. In order to find them again later, I will try to collect links here, in an updating list. At the start, at least, I will put newer entries on top. I doubt I will confirm any link stays alive beyond the time I paste here.
update 3 September 2021
tweeted by Dylan Wiliam -- Stella's Stunners
https://www.mathstunners.org/
update 27 August 2021
Teaching through problems worth solving. Alicia Burdess et alia
http://www.aliciaburdess.com/uploads/2/4/7/6/24763920/3.0_teaching_through_problems_worth_solving_grade_8.pdf
update 25 August 2021
Gleam Math
https://www.gleammath.com/blog
Initial links 21 August 2021
Peter Liljedahl's website
https://www.peterliljedahl.com/
Building Thinking Classrooms website (under construction?)
https://buildingthinkingclassrooms.com/
Big Wheel task (from Thinking Classrooms website)
You are standing in the living room of your ground floor apartment when a giant wheel rolls slowly past your window. The wheel is huge with a radius of 100 miles and when it passes the window it completely blocks out the light from outside. The question is, as the wheel begins to pass the window how will it appear to block out the light: (a) from the top of the window moving straight down, (b) from the side of the window moving straight across, or (c) from the top corner of the window moving diagonally down and across.
Video Game arbitrage (from Thinking Classrooms website)
I buy a video game for $10. I then sell it for $20. I buy it back for $30. Finally, I sell it again for $40. How much money did I make or lose?
Egg Timer task (from Thinking Classrooms website)
I have a 4-minute egg timer and a 7-minute egg timer—the kind that you turn over and let the sand run through. Can I use these to cook a 9-minute egg? If so, how long will someone have to wait for their egg?
Google Doc of tasks (owned by Kim Brown, I believe)
https://docs.google.com/spreadsheets/d/1rFKbmtaaSS_KiMr0jt9ZS8MQYp1Uxr5XINEDh9uycNA/edit?usp=sharing
Google Sheet of tasks (owned by Jeffrey C Hamilton, I believe)
https://docs.google.com/spreadsheets/d/1NSR8PlF2UaVT4tLTpCw-AYOfGkFz044lTkhHXb1-sH4/edit?usp=sharing
Orchestrating Discussions -- 5 practices per NCTM
https://t.co/RDeRdWMoPY?amp=1
Saturday, March 27, 2021
Typing in German
I have a US laptop (no surprises there).
But now, in Germany, I must at times type things in German. Here are the things I've learned so far.
First, I had to install the US International keyboard on my Windows system. I boot to my default US keyboard, but when I need international characters the key combination Shift+Ctrl toggles to and from the other keyboard. On the international keyboard there is a difference between the left and right Alt keys. The right one is sometimes called Strong Alt, or Alt Gr.
Important characters in German:
Germany still uses the character for some double-s instances which looks like a Greek lower-case beta - ß. I produce this character with AltGr+s.
Germany also sometimes uses two dots over the a, o, and u characters. There are two ways to produce these in US Intl mode.
1) press double quote " followed by the vowel. ä ö ü. This causes trouble when you want to start a quote with an A, O, or U word. In these cases, type a space once after the double quote, to produce a double quote. "As I show here."
2) the second method uses AltGr key combinations.
For ä hold AltGr+q
For ö hold AltGr+p
For ü hold AltGr+y
Currency here is the Euro. AltGr+5 gives € the Euro symbol.
The issue I don't have a good solution for yet is quotation marks. In Germany the most commonly used quotation style begins with a double quote at the base line curving towards the quote, and ends with a high double quote also curving towards the quote. For example: He said „You must learn German.‟
I have not yet found a key combination the produces these characters. I think that if I had a full keyboard with numeric keypad I could type the Unicode (Unicode 201E and 201F) but I'm using a laptop keyboard. For now I usually ignore the issue and use US style quotation marks. But, for extreme circumstances I've stored the correct quotes (double low 9 quotation marks and double high reversed 9 quotation marks) in a reference document, from which I can copy and paste.
In some MS Office applications I can automate this with autocorrect, but I'm not always in Office.
Saturday, February 13, 2021
Learning German (Deutsch Lernen)
In my imagination, one benefit of my move to Germany was the possibility of becoming a learner again. Not the learning from idle curiosity, as when I attend advance math seminars and workshops, but a learner of necessity. In reality many Germans have good communicative competence in English, but to really get by in this country and culture I need to learn German.
Why is becoming a learner of value to me as a teacher? I am reminded of some of the issues that learners face, and so can re-sensitize myself and, perhaps, adjust my teaching practice to become a better teacher.
I got two lessons yesterday. Lesson one; communications. My German teacher for some reason changed his Zoom information, and he posted a message with the new log in information in a Whatsapp group that most members of the class belong to. I suppose many people keep their phone by their side at all times and as soon as a message comes in to social media, they stop what they're doing and read it. I don't.
I have a full-time job as a teacher, and I don't interrupt class to stay up-to-date with the social media world. By the time I got to my phone, the message in question had been pushed far up the thread, buried in smiley faces and people chit-chatting about various uninteresting (to me) topics. It never occurred to me that my instructor had posted a vital piece of information 8 or 9 screens up the scroll, and I didn't look.
So when class time came, I attempted to log in. And I sat in the waiting room. I glanced at whatsapp to see if there was anything happening, and there was a note from the teacher saying, "sorry I have problems to login now. gimme a sec pls." So I waited. No idea he was talking about the new room number.
After a few minutes the chat in whatsapp stopped, but I still had not been admitted. So I waited. I checked my email to see if there were any notifications. And I waited. I sent an email asking if they're still having trouble. I checked whatsapp again and there was no information. So I posted there asking to be let in.
Only then did the teacher send a second message about the new room. So I switched and got into class a half hour late. To an empty room (it turned out that everybody was in Breakout Rooms working on some exercise). When breakout rooms closed and everyone came back, I was left to fend for myself with no briefing on what I had missed. Language classes are very fast-paced. I was allowed to experience in much greater depth than I ever hoped for the feeling of being completely lost in a class, where everyone else appears to understand, and not wanting to ask for additional explanations. Wow!
One of the ideas I've been increasingly convinced of is Cognitive Load Theory. I was 30 minutes behind, I struggled to leaf through the pages of the text book which were clued to me by the current topics in class, and tried and tried to catch up. To no avail, I believe because I was already so far behind that my "working memory" was stretched beyond capacity and I could not get enough additional information in to sort things out. Another excellent reminder, as this is so often the feel that students in Math class have.
What I wanted was for the teacher to pause, and bring me up to date. Even if not reteach everything, at least give a summary of what had passed.
I hope this experience helps make me a better teacher. While I'm not happy to have experienced it (it was extremely frustrating and irritating) I hope to use this to inform my own practice.
Monday, November 9, 2020
Immigration Office
I went for my interview with the Immigration Officials. Several people at work assured me it is no big deal, and mostly a formality, but perhaps unconscious bias left over from a Cold War childhood had me nervous about dealing with a German bureaucracy.
Fortunately most of my transition to Germany has been shepherded by Relocation Agency, hired by my school, and they have overall done a very good job of taking care of me. My agent, Cathy, met my wife and me at West Banhof Station, and drove us to the Immigration Office in downtown Frankfurt. Frankfurt is not really that big a city, but it seemed to take a long time to get there. Maybe there were one way roads the forced a circuitous route. Although I usually have a very good sense of direction, I lost track of the turns until we pulled alongside a long building that had the feel of "government offices."
As we pulled into a parking spot I noted a long line of people waiting to get into the building. We exited the car and joined the line. The line did not move at all. I assumed we were all there for appointments with an immigration official, although the building itself seemed to be a generic government office building, with a variety of departments.
At some point the guard began letting people in. He'd check their proof of having an appointment, and let them in by ones or twos. I didn't worry about it at the time, but I suppose we were the only trio in line.
When we got to the guard, our Relocation Agent showed the letter confirming our appointment and told the guard, "we have an appointment." He indicated she can go ahead, and my wife an I tried to follow. He stopped us. I tried to pantomime that I'm with her, pointing at the Relo Agent, and he seemed to accept that. But he wouldn't let my wife through. It was as though he couldn't conceive that there might be a grouping of three. We stopped, tried to explain, the Relo Agent noticed and came back, waved the appointment letter. The guard wasn't buying it.
Finally he let us through, but as his parting shot, scolded my wife for having her mask a bit too low on her nose.
Into the building. Down a hallway. Up a stairway. And from that point on, all frames of reference disappeared. It was a loooooong hallway, uniformly grey, with doors on both sides. The only markings were generic office numbers -- 1.073, 1.074, 1.075, and so on, door after door, down the almost featureless hallway. Finally we got to the end of the hallway and turned left. To another long featureless hallway. How long can this continue? I felt as though I was in a Kafka story. The hallway ended in a doorway to the outside, which I saw led to a bridge to the next building. Where I found yet another long hallway.
Eventually we got to a waiting room, where we were to wait to be called. The appointment was just for the two of us - the Relo Agent could not go in with us - so she prepped us for what to expect, but still reassured us that it was essentially a formality.
And it was mostly a formality, except I got scolded for working prior to getting a work visa. For a few moments they had me sweating. Then the interviewer said it would be okay since it was only a few weeks, so she'd ignore it.
From there it was bureaucracy. She filled out forms. She glued my ID photo to one of the forms. She scanned four of my fingerprints (both index fingers and both thumbs). She gave me a voucher and told me to go down to the payment office to pay the registration fee. I did so and brought back the receipt. She put an official-looking stamp on one of the papers and handed it to me, and said that was my temporary permit, and I should receive the actual permit in the mail. She repeated the process for my wife. And we were on our way.
And thus went my interaction with German bureaucracy. I have legal permission to work here, as does my wife. and we continue to adjust to our life.