## Alg II Files: Matrix Multiplication Application #MTBoSBlaugust

I’ve already blogged most of my matrix notes on this post (and as always, you can find all of my Algebra II Files and FAQs here), but I did do a new introduction to matrix multiplication that I liked:

(NTM file here, practice file here) Sure, you have to do a little teacher manipulation to make sure that the second matrix on the calzone example is a column matrix, but I think it really helps to see why we multiply matrices like we do, and what the resultant matrix tells us.

It also gives us a reason to play this in class:

And as an added bonus, a pretty worksheet with a calculator picture and arrows! (Also I totally skipped finding determinants and inverse matrices by hand. Sorry, but sometimes you gotta ruthlessly cut stuff.)

(file here) Yes, it is required that you play Jackson 5 after the last problem. REQUIRED.

## Sunday Summary

Posted on 1 comment

3 things to share

1. Man, don’t you hate it when you figure out a better way to teach something the day after you teach it?  Although trig equations went pretty well this year (well, we’ll see tomorrow on their quiz), I think next year I will structure it differently. Here’s where we started:

Next year, I’m going to start at the end with the calculator/desmos, with a -4π to 4π window to discuss the general form.  Then do some examples with θ between 0 and 2π, then non-calculator examples.  Then on day 2, graph 2θ (or θ/2) on the same graph to discuss getting more/less answers.  If you’d like to modify this for me (doesn’t hurt to ask, right?), or if you want to use it as is, here is the .doc file (with bonus homework at the bottom!)

2. Now, day 2’s note-taker-maker, I’m kind of in love with. (ok, technically this was day 3 because I ended up teaching day 1 slowly)

The only thing I might change is super-reinforcing the ZERO product property rule is not the “ZERO or sometimes 2 or 3 or -7 product property rule” because some of my students are still having issues with that. (btw, Snoops is dancing because it’s already factored.  Also, it is super fun to have a kid ask later, “How can we solve this?” and you reply, “Cute and cuddly, boys!”  File link.

3. I finally figured out about 3 years ago how to make linear programming less painful…get the mechanics of it out the way first!

Let them spend a day finding the feasible region, vertices, and max/mins.  Then the next day you can focus on the finding the equations from those long scary problems and the rest is the same as these notes.  Much less stress than trying to introduce all of it the same day.  File here.

2 good books I’ve been reading

We took a quick weekend trip to Chattanooga last week where I started David Benioff’s City of Thieves and could not put it down!  It’s like a buddy cop movie set in the absurdity of World War II.  It reminded me of Anthony Marra’s Constellation of Vital Phenomona, one of my favorite books of the last few years.

Hector Tobar’s Deep Down Dark is the reason I haven’t gotten anything done today!  How did he make this so compelling when I already know the outcome?  I’m about to go draw a bath and try to finish it tonight; it’s such a page turner!  And don’t worry, he does a really good job making sure the reader doesn’t get lost with all the people in the story (I’m horrible at remembering names in both book and real life.)

I have to write a unit plan about complex, polar, and parametrics using some premade lessons (and adding others as I see fit). The premade lessons are really expecting a lot from our students and I’m not sure if I will get the outcomes desired by using them (unless the desired outcomes are tears and frustration).  But I’m having trouble finding a lot of great stuff that I can easily replace them with (I have a few things thanks to @mrdardy and @crstn85).  So if you have some cool stuff to share, please do so!  The state of Alabama will thank you!

## #MTBoS Sunday Summary

My week:

Algebra II w/ Trig

We took our first test, which was a GREAT segue[1] into growth mindset and overcoming setbacks.  Although they didn’t knock it out of the park, I had fewer really low grades than previous years, so that’s a good sign.  This is usually a tough test and I think I need to either (a) break it up into 2 quizzes or (b) actually follow the notes that I leave myself every year that say “DO MORE DAYS OF ____”

Then into functions with this beautiful Note-Taker-Maker[2] that I stole bits and pieces of from everyone, but I think mostly from mathequalslove.

Friday we did the ever-popular graph stories, but I made it into a worksheet because I do not have time for scissoring.  They worked in groups and I paired groups up as they finished to discuss answers.  Then when everyone was done I brought out the talking dog.

No, it didn’t actually talk. I’ve been having an issue with students not listening to other students talking, so I thought I’d take a cue from GWWG and Mr Healy and start the rule that you can’t talk unless you have the talking dog.

So the dog was passed around as we explained and discussed our answers to each graph.  And what do you know?  It worked!!  Not 100% of the time, but they were listening a lot more than before. Some of the kids had great explanations, too, including “we first thought it was this graph, but then when we met with another group, we realized….”  Win!

PreAP Precal

Holy moly, definitely some ups and downs this week with discovery learning.  All of the kids are working super hard at trying to figure out what I throw at them, but they are lacking in (a) math skills and (b) seeing math connections.

We spent about 1.25 days on translating linear equations to discover our “new” point-slope form: y = m(x – h) + k.  Worksheet here.  It went really well and was a good lead-in to piecewise (“isn’t it so much easier to write the equation of this guy using point-slope since we don’t know the y-intercept?”)

We also spent 2 days on average rate of change, worksheet here. (I’m pretty sure I stole this from someone, too–I really need to work on documenting my sources!)  The first side of it went great, but I need to reword it so they understand we’re doing the exact same thing on the back!  Just calling it a different name!  Really!  That’s it!  Then I wonder to myself, would they have made better connections within the same time frame if I had lectured for 20 minutes on AROC, definition, formulas, etc, then let them work with applications of it for 1.5 days?

So even though it may get me kicked out of the MTBoS, I think I’m going to stick with introducing a topic as a class first, then letting them loose on going deeper, rather than letting them loose to discover the topic but running out of time to go deeper.  Plus, I think based on this: (poster available here) I’ve been in the panic zone as a teacher way too much this year and need to scale it back to be in the learning zone.  I need to keep reminding myself I don’t have to try everything that I learned at TMC during the first month of school!

[1] I’m not going to lie to you; I just found out last year this is word that people are using when they say “segway” as in, “Using (person, birthday) as a function example allowed me to segway into mentioning I don’t like Starbucks.”

[2] Notetakermakers (or “NTMs”) are what I call my graphic organizers.  Yes, I make one for each section.  Yes, I do use a lot of paper.[3]

[3] Dude, I don’t know why the superscript is showing up as just tinier script.  I’m using “sup” and everything.  Here’s a subscript example: [1] which looks to me exactly like the superscript.  Sometimes I hate everything about wordpress except for the fact that I get to use “megcraig.org.”