Showing posts with label Algebra. Show all posts
Showing posts with label Algebra. Show all posts

November 13, 2017

Matrices - the Basics

I've been writing a lot of material lately. Why are matrix lessons so hard to find? I understand that they're plus standards in CCSS but even if you don't teach them in Algebra 2 someone should be teaching them somewhere...?? Anyway, it's been great in that I have total control over the difficulty level, language and content focus. Not so great in that it takes a ton of time. But since I put all this time into things, I'm going to share so that the time was worth it!

I was out (at ATMNE) for the first day of the unit so I made an introduction packet from my textbook and David's lovely post on matrix multiplication. The students who were willing to read and take some baby risks did great. The students who were scared to try informed me that they couldn't do it since I didn't teach them how. I need constant reminders that these are learned behaviors. Given enough time and consistency I can teach them new behaviors. But omg is it hard some days!

To determine what students had learned from the packet as well as see what details they would attend to, we did a WODB the next class. After my last post I got some more feedback and decided on this set. Kids found reasons for all four in every class! I was surprised that the non-square matrix didn't get the most votes since it's the one that jumps out to me.

Then we practiced matrix multiplication by comparing matrix multiplication to the multiplication of numbers. For some students this sequence flowed really nicely. We did a problem from the homework and someone asked if we always had to bring down the matrix on the left. Cue a couple problems that follow a*b vs. b*a. Lovely counterexample of the commutative property for matrix multiplication. The next pair of problems has students multiply by the identity. For students who were paying attention they caught on to the pattern quickly and realized that this matrix was special. Students who weren't paying attention got extra practice multiplying matrices. I let them in on the 'secret' that mathematicians are lazy! They look for patterns to make their work easier and we should be like mathematicians as we work. It's a tricky balance to structure a class so that students are always looking for patterns but to make sure that they aren't just assuming there's a pattern because there always is one. That was one benefit of starting with testing the commutative property - in that case the thing to notice was the lack of a pattern! Finally we multiplied some inverses. Another benefit to the pattern finding structure is that students compared work with their group when they weren't seeing a pattern, they found mistakes faster than in a random set of practice problems. I chose my inverses very carefully which allowed students to recognize two aspects of inverses (opposite signs and switching a with d). We finished off with some homework on all the operations they've learned so far.

A few students asked during all of that rather tedious matrix multiplication practice what the point of these things was, when would anyone ever use this?? So I told them about graphic design using a matrix to represent all of the points of a figure and operations with other matrices to transform them on the screen. I could've sworn I saw a video on them using this process for the fur in Monsters Inc. at the Pixar exhibit at the Boston Museum of Science but I can't find the video online. I could, however, make up a problem set to demonstrate the process by 'animating' a triangle. This might have been my best lesson all year! It was last block before a long weekend but yet students found this lesson very approachable and got some self checking practice applying matrix operations. Bonus- I enjoy activities that blur the (non-existent) lines between algebra and geometry.

Most students finished their transformations with time to spare (in an 80 minute period) so I had another practice sheet ready to start in class and finish for homework. My colleague and I like my textbook's problems with variables and expressions as entries in matrices. Some of the entries are self checking, others make simple equations and students get some practice solving one variable equations (which, yes, my algebra 2 students do still need). However, no one on the internet has these lovely problems, including our Kuta Software. So I searched class zone (I still don't understand the structure of that site but I'm learning, kinda) and compiled all the ones they wrote on an additional equation practice sheet.

Next class we'll do some other applications of matrices and row games to review the basics before heading into systems.

What else do you have for matrices? Where on the internet are these lessons hiding?

November 11, 2017

Explore Math Project and DREAM

Last week was both the end of the quarter and ATMNE. I got the chance to see Tracy Zager talk (both her keynote and her workshop) and reflect on how first quarter went. Tracy's keynote was about mathematical inquiry. One method of allowing kids to ask the questions is to provide students time to play with math. Her daughter wondered why we DEAR (drop everything and read) but never DREAM (drop everything and math). After the talk, some of us who teach high school were discussing what this might look like at our level. I suggested that my version of Explore Math is one option, after all one of the columns is titled play!

This year's version of Explore Math asks students to explore something from one column per quarter and then share briefly with the class. I assigned it in all three sections of Algebra 2 as well as my honors precalculus. I've really struggled with my Algebra 2 classes and part of it is that they don't enjoy math, at all. They see every aspect of the subject as painful and it is taking every teacher tactic in my bag to convince them that math might be interesting to think about. I hoped that they would find something to grab their interest when completing this project. However, students continued to resist - I'm too shy to present, none of those 17+ options appeal to me, I don't know how to [fill in the blank]. When the first person presented on a mathematician they realized that I wasn't asking for a giant research project and almost all decided to also look up a mathematician, but there wasn't much exploration of math happening. Don't get me wrong, it was awesome to see my diverse students represented in the diverse mathematicians they chose but most didn't even look up the kind of math they studied. Maybe step one needed to be seeing that someone like them did math before they could be convinced to take another tentative step toward enjoying math? Here are the statistics from the first round:

Precalc:
61% mathematician
0% didn't do
2 recent articles, 2 recent topics, 1 unsolved problem

Alg 2 (3 sections):
64% mathematician
32% didn't do
1 brilliant.org problem

59% mathematician
36% didn't do
1 grad level math

59% mathematician
41% didn't do

I'm thankful I made this a year long project so that now for the remaining three quarters students will have to choose other categories. It seems wrong to be forcing my students to play, but after many years of learning to resent math it's going to take a strong shove toward playfulness to get them to consider it as something that they could engage with independently. (These results have a little bit to do with the project being homework, but I provided time in class on several occasions to work on this or other make up work.)

Tracy asserted that allowing kids to ask the questions is 1) intellectually honest, 2) a good way to teach and 3) important for equity and access. I have been trying harder to make the structure of class transparent to students. For example, I've shared with them the 'secret' that mathematicians are lazy! So they look for patterns to make their work easier. Most lessons involve us playing with problems to test some ideas and then generalizing our results, but when students aren't driving the questions it doesn't feel like playing. A recent lesson on matrices flowed beautifully for some students but others were so caught up in the drudgery of multiplying matrices (because integer operations require significant brainpower) that they weren't seeing the overarching ideas on their own. Turns out it's hard to recognize the significance of the identity matrix when you forget whether 5*0 is 5 or 0. So we're working our way toward 1) and 2) with some students feeling like mathematicians each day. What about 3)?
"The person who poses the question is the person who frames the debate."
When Tracy said this sentence I stopped, wrote it down, tweeted it out and only partially heard her next several sentence as I grappled with this huge revelation. Politics can be decided based on who poses the question and how they frame it. How do I give my students this power? How do I make sure that my students recognize this so they can question the premise of others questions? And, honestly, how do I even consider doing any of this when I have two new preps this year? I look back on the things I did last year and regret how many of them I've let drop this year. And then I remember that I only had two preps last year and I'd taught both of them at least 3 times before. While I should cut myself some slack I'm not going to give up entirely. Up next is solving systems using matrices with technology which sounds like a good time to mix in some messy data, hopefully I can find some worthy data sets for students to play with. They can ask the questions. They can judge others' questions. We can do some aspect of this important work each class and hope that by the end of the year students see their relationship with mathematics with a bit more positivity.

October 31, 2017

Matrices WODB

I've managed to avoid teaching Algebra 2 for all but one year of my career (prior to this one). Between Algebra 1 and Precalculus I am familiar with most of the topics in the course, but matrices don't appear in either of those courses in our sequence. I forgot how much familiarity with content makes a difference when prepping! Pulling from our textbook and David's lovely post on matrix multiplication I made a packet to introduce matrices and their basic operations while I'm out. I wanted to start the next class with a Which One Doesn't Belong? but I couldn't find one. So I thought I'd make one. I started out thinking about dimensions- the top right is the only one without a dimension of 3, the bottom left is the only one without a dimension of 2. Then I thought we could play with the numbers to get something interesting.


But when I was chatting with my colleague we were struggling to come up with what other reasons we could set up. I know that when Christopher first started making these he asked people for four characteristics and then made each shape using just 3 of the four (so each one wouldn't belong due to the characteristic it was missing). We tried to think what other characteristics we could include and decided to use the scalar multiplication and equation solving from the packet to build other aspects. I also made the sum of the digits equal 10 for three of the four just for fun.


But when I tweeted this set I still wasn't getting the kind of responses I was hoping for. And I am confident this is because I'm not familiar with matrices. I'm going to have to spend some time familiarizing myself with inverses before I can teach them. By the end of the unit I'll have an entirely different idea about what important characteristics of matrices are. So until I get there, help me out? Describe a matrix using four characteristics and let's see if we can build a good WODB together!

September 9, 2017

Start of Year: Algebra 2

The last time I taught Algebra 2 was in 2010-2011. It was my first year at this school and I had a class of kids who were not excited about math - some had only managed to get credit for Algebra 1 by attending 3 weeks of summer school that everyone passes. I wrote at the end of my post on student reflections on the course: Thank goodness I'm not teaching Algebra 2 again! And I managed to avoid it for many years. The thing I hated about teaching Algebra 2 was it felt like Algebra 1 all over again, so when administration asked if I would move to Algebra 2 this year I said yes on one condition - that I could skip the review units. Because if kids have been learning about lines since 7th grade, why would I teach them yet another unit on lines? You say they don't get it? Who cares! There is so much math in the world, I would hate math too if all we ever did was repeat a mantra of y=mx+b, rise over run for five years in a row (linear review has infiltrated geometry too since kids take a state test on algebra and geometry that year). One, I don't particularly care if they can write the equation of a line from memory. Two, they're more likely to realize why lines are special if we do some stuff other than lines and then compare. But really, there's so much cool math we never get to, let's just move on! So I talked to a coworker who has taught Algebra 2 for the last several years and then my co-teacher (who also co-taught with that same coworker) and I sat down and made a plan together. We have a timeline for units that we will eventually add standards to as we get ready for the transition to standards based grading next year (this is the reason I got moved - they took two of us from the Algebra 1 SBG planning team and moved us onto other teams to repeat the process).

Aside from the essential content of Algebra 2 I have a few goals:

1) Expand students' idea of what math and mathematicians are by doing the Explore Math project. Instead of waiting until the end of the year I plan to have students complete one column per quarter which means frequent short presentations throughout the year.

2) Provide space for talking about big ideas, current events and equity issues. I'm not planning to do weekly homework the same way I did last year (I don't have lessons I like for this course, I can't be writing lessons and deep weekly assignments) but I hope to incorporate the same ideas in my class assignments. In fact, already started on day one! (below)

3) Push students to do more writing. I've always asked students to reflect at the end of class but with younger kids and a large number of them ELL or students with disabilities I asked for two sentences. I provided a third of a page per day this year, I'm curious if that will be enough or if I'll need to specify my expectations (and possibly modify for the smaller number of ELLs and students with disabilities). Inspired by Jonathan I'll be asking for longer explanations on assessments as well. Last year's weekly homework meant students regularly wrote persuasive paragraphs. This year I hope to continue to encourage debate while including some more expository writing.

4) Employ the strategies of visibly random grouping and vertical nonpermanent surfaces to improve students' confidence sharing their ideas with others. Marian recently tweeted about helping students find their inner rebel, that's definitely a factor in my goal of confidence boosting!


First lesson:

We are starting the year with piecewise functions (a tiny bit of linear review with a big focus on domain, range and fluency interpreting graphs). I told them the story of the weather caused by Hurricane Harvey in one location and asked them to graph stream elevation at that location. Then we talked about how data is more complex than the over simplification of our graphs - it could be raining at the same time the stream is draining and every time one of those rates changes the graph reflects it. Reality is way more bumpy than my grossly over simplified story. Next I showed them a graph of stream elevation at a different location and asked them to tell me the story of the weather there. Of course a verbal description isn't enough, so we also described numerically (domain/range) and with equations. After discussing two graphs in depth I projected them with two more, in a WODB format. Kids decided which one didn't belong, I emphasized the multiple right answers and they wrote their reasons on sticky notes to add to my display in the hallway. I was interested to find that some students asked for vocabulary "what's it called again when it goes over the red line?" to put their explanation in context. Throughout this conversation I shared stories (here's a timelapse my friend took, he didn't get flooded. See how this stream still wasn't drained on the 31st? The highways weren't drained until yesterday!) and invited questions. Yes, I picked this context on purpose, I want to talk about big things happening in the world in this class. We didn't specifically get into ideas of equity but I would like to think about how I could include something like this cost analysis soon (maybe it will fit in systems, that's our next unit). Slides here.

Since we had almost a full block on the very first day there was still some time left for students to get started on a problem set. I sent them to the boards to analyze other piecewise situations (for three problems I gave them the context and for one I gave them the graph).* You may notice I haven't mentioned the syllabus yet, I gave it out at the very end of class and told the kids to read it for homework but we would go over each aspect of class as it came up rather than me explaining it that day just for them to forget. And then I explained the journaling aspect of class and had them reflect on day one!

Second class plan:
Most students didn't finish their first problem of the problem set so we'll need to spend a bunch more time on that. Unsurprisingly they didn't all remember how to write the equation of a line so I'll do a very mini review of the various forms available to them and then send them back to their boards and groups to finish. I think I'll have them do Sara's 100 numbers activity to talk about how to be good group members first. If groups finish the problem set with time to spare then they can play on waterline. I'm saving function carnival for the next class - we'll complete it, do the follow up activity and then they'll have to write the piecewise equation for bumper cars and explain it for homework.


*Amazingly my evaluating administrator stopped by while one class was working on these problems. Teachers with tenure (like me) are supposed to be on a two year evaluation cycle but at the end of last year I got placed on a one year cycle. The concern was my classroom management and my evaluator asked why I didn't have my algebra 1 students up working at the boards the same way I used to with my geometry students. The reasons are complicated (as most aspects of teaching are!) but the point is that he wanted kids up at the boards at the end of last year and he saw my kids up at the boards the very first week this year. He was excited and I feel significantly less dread about the evaluation cycle this year!

May 18, 2017

Grading on Proficiency Scales

Our district is moving toward standards based grading. It's very exciting because we're doing something purposeful and with forethought and planning. Next year just the core 9th grade classes will use it. I've been doing a modified version of standards based grading for years, however this will be different. We are doing truly standards based grading as opposed to skills based grading. We will be grading against 11 standards in algebra one and each has a list of skills for students to master. The grading happens on a proficiency scale like this:


We're really struggling with how to track students' progress. When we enter grades into our online grading system we'll only enter the number for the whole standard. So a quiz early in the unit might only assess some skills so the maximum score will be a 2. Later in the unit when the maximum score will be a 3, we won't have a way to record in the online grading system which skills a student mastered if they don't reach a 3. But if kids need to do retakes we need some way to track what skills they need to provide evidence for.

Options we've considered:

  • paper copies of proficiency scales, highlight each skill they master, show them to students but keep them in the room (binder or crate of hanging file folders)
  • paper copies of proficiency scales, highlight each skill they master, give them to students and also track in a spreadsheet
  • start using google classroom, digitally highlight proficiency scales (there's apparently a way to attach rubrics to assignments?) so student and teacher can see
Has anyone done standards based grading like this before? Any suggestions?