Saturday, September 29, 2007

Angular Speed

We started working on linear and angular speed, and I presented a few examples of what you would calculate and how to calculate, but some students still struggled. Today in one class this seemed to work. I was looking around for something familiar to link their knowledge to, and lo and behold, THE CLOCK. So I asked them to quietly ("let other people figure it out for themselves") find the angular speed of the second hand of the clock (I had to call it the "red stick" for the students that didn't know the term). "Ahhhhhh". Then we worked on the angular speed of the "long black" stick (minute hand) and the "short black" stick.

I also handed out colored paper that had a large unit circle on it (I bought it special for you at the store) and thin spaghetti (everyone gets one especially chosen for them). We worked on initial and terminal sides of angles in standard position. Then to start discussing reference triangles, I said that they were joining a math cult today, and every time we passed each other in the hall we had to repeat our special phrase: always drop the perpendicular to the x-axis. We practiced our cult voices for a bit. Then I assessed their reference triangle knowledge with the spaghetti. Hopefully, this will prevent students from drawing their reference triangles incorrectly as some have before.

Wednesday, September 26, 2007

Learning Greek

Last year in precalculus I had each student pick a Greek alphabet letter out of a hat, and they were to make a small (8.5" x 5") colorful poster with the capital letter, the lower case letter and the pronunciation of the letter. Then I hung those around the room, so we had a reference when we were using the letters as variables in trigonometry. I liked the activity, but then the students only got familiar, for the most part, with one letter. This year I made an "elementary school" type sheet where they have to trace over the capital and lower case letters 4 times each while simultaneously saying the pronunciation. They'll get bonus points if they can recite them all in order by memory. I'm liking this activity, so now I have to possibly make the letters myself because I still like them displayed. If anyone wants a copy of the activity, I'll send you one via e-mail (

I'm also excited about my teacher website. Whoever suggested and google calendars, Thank You. They were both easy to use and link together, and in just one weekend I created a usable site. I made it as a homework assignment for the students to have their parents visit the site and either send me e-mail or call that they did so. Yay technology.

Saturday, September 22, 2007


We started trigonometry at the end of last week, and I know from past experience that my fraction-phobic students have trouble with placing pi/3, pi/4, pi/6, etc. angles in standard positon, so I tried something new this year.

I drew a semicircle (flat-side down) and made up some story that involved having and "em(pi)nada" for lunch and said it was so delicious that other teachers wanted to share it with me. I had them draw 4 em(pi)nadas and draw how they'd slice them in pie cutting fashion into 2, 3, 4, 6 equal parts to share and eventually they shaded the 1st piece (thinking of angles in standard position). They had no trouble slicing them equally, and I think it helped later on when I linked pi radians to 180 degrees, and they then drew pi/3, etc angles around the circle.

Then I introduced radians by first saying that for so-and-so's birthday I gave her a circle, and her mom gave her a string, and so-and-so was SO bored that she decided to do math by cutting the string the length of the radius, and she wanted to see how many times it would go around the circle. They were then to discuss how many times they thought it would fit. I got various responses, 3, 4, 6, 10... We finally got to the fact that you're just measuring the circumference. They then proceeded to equally tell me the formula for circumference was pi*r*r and also 2*pi*r. So then I had to sing them a song a student taught me, and then we all sang it together a few times:

Twinkle, twinkle little star
Circumference equals 2, pi, r.

Lovely (it brings a tear to the eye). We then defined radians.

Anyway, after I used my math tools (thin spaghetti to sweep out angles on the overhead), and we practiced placing various radian angles in standard position, we called it a day.

An interesting side note: another teacher friend mentioned a while ago how he linked the clock with the unit circle and that seemed to help his kids place 30, 60, 45 degrees more successfully around the circle. Well, I also brought that up, and in a side note, one student mentioned, "you know, I have a hard time reading analog clocks. I never learned, and now it takes me a while to process it."

Wednesday, September 19, 2007

Quick Assessment

Last week with about 8 minutes left of class, I handed out scratch paper that was cut into 4ths, 1/4th to each kid, and put 3-4 quick "pop quiz" questions on the overhead (3 math, and 1 "spell my last name" since they always mess it up and it eased the tension of a "pop"). They could use their notes but not talk with anyone. We happened to be studying function composition. I told them to write down the problems, show their work, and box their answers.

They took it seriously because it was for a grade. I liked it because I could walk around and scan their answers and see who was getting it and who wasn't. After a couple of minutes anytime I saw a wrong answer, I quietly mentioned to the kid that they should check that problem. That way, later I had an easy time to grade them, the kids felt better about the "pop"ness, and I then could concentrate on the 3-4 kids that I saw just weren't getting it and help them through quickly or suggest they come in for tutoring later.

Saturday, September 15, 2007

Sleep Deprivation and the Modern Teacher

1. We were supposed to calculate (for a grant) how much extra time we spent after school last year tutoring students. So I figured on average I spent 3 extra hours per week at about 30 weeks that year. Wow, I calculated, I spent 900 hours tutoring! I rock (though apparently not at multiplying 3x30).

2. As the week goes on I get more and more sleep deprived (that's my excuse preamble for the following). I also daily wear my wedding ring that I never take off, and many other silver rings that I take off at night and put back on daily. So on Friday I get to work, and to my classroom, and I instantly feel and see that I have all my rings on except my wedding ring (of almost 13 years). Gasp! Oh no! Did I get too skinny (cough) and it slipped off on my way from the car to my classroom? I obsessed about it all day. That night, I went home and saw that it was in my ring tray. I don't even remember taking it off. I don't remember realizing it wasn't on all morning. I don't remember seeing it and sifting around it in the morning while I'm putting on my other rings.

3. I had this lesson that was working really well on symmetry of functions (even/odd/neither) on Friday (remember, in my defense, I'm TIRED), and I divided my overhead slide into 3 rows and would graph, describe, give the rule, and give an example for each type before moving on to the next type. I was running out of room on my slide, so I slid (tee hee) it over to the left and continued writing on the overhead glass to finish up the EVEN example. I then used my spritzer bottle and rag to clean the glass before moving on to the ODD example. I got through the graph, the description, the rule, slid the slide over, and then looked above at my EVEN example, and realized that, Oh no!, I forgot to give an example for the EVEN function, and here I am on the ODD example. So I start walking them through the steps of the EVEN example, and I'm patiently waiting for them to continue, and a student asks, "didn't we just do this?". Oh my.

Thursday, September 13, 2007

I'm Scary

School has been in session for almost 3 weeks now. I've given my 1st test, and there have been about 5 homework assignments, and I've passed out current grades. Therefore, various students with low grades came in after school today to get tutoring to boost their understanding and their grade. I keep mentioning in class that I'll work with the students and they're welcome any time and if they make improvements from whereEVER they are in their understanding, they'll pass (or better) my class.

It's been my experience teaching precalculus and calculus that the students are finally, "oh, NOW I have to study to actually get a good grade. ... oh, NOW I have to actually do and do properly my homework ... oh, NOW I have to come in for tutoring to make sure I get it."

There were about 8 students in my room after school, and I'm circulating around, and I'm helping this one girl with domain and range. We were working through a problem. I'm prompting her for answers. I don't think I was rushing her. I paused and waited for her responses without any physical gestures of impatience or interrupting. At one point, as I'm waiting for her response, I could see she was flustered, and she said, "oh, I'm so nervous."

Wow. I didn't think I was that intimidating. My perception of myself and how new struggling students must see me are apparently not in line. I made a joke of it, "I know. I'm scary." and we went on. But it made me remember that just because I think I'm a nice and patient teacher, a student that's just meeting me for the 1st time and is struggling sees a different person.

Sunday, September 09, 2007

Piecewise Functions

The following demonstrates why I don't do "formal" lesson plans before my lesson. Well, this and the fact that I'm a last-minute (post-last-minute?) person. I eventually do get the plans down on paper, since I use them the following year to see what works and doesn't work.

I was introducing piecewise functions to my precalculus class. I started with an example of a power company in town and suggested that they may offer incentives to people who use less electricity, so if you use less than or equal to 500 kW per month, they charge you 10 cents per kW, and if you use more than 500 kW per month, they charge you 15 cents per kW. I then gave them the disclaimer that I had no idea how much a kW was and if this was at all reasonable. (future assignment for the class and me: find out how many minutes of light that is). Then to make sure they got it, I asked them to put on paper in calculator-ready form, how much my bill would be if I used 600 kW last month. I wasn't even thinking about the ambiguity, but a great question came up: is it 15 cents for everything since you went over, or is it only 15 cents for the 100 kW over? (we went with the 2nd option).

Then we started drawing the graph, and decided that there would be an initial service fee of $20 even if you didn't use any kW. I asked them to discuss in their groups the axes labels and what the left part of the graph would look like (before 500 kW). We also did the right side. Now here is where in the past I would have breezed through this and shown how it was piecewise and then went on with another "math-class" piecewise function to work with. But a student pipes up with, "ooh! I know the equation of the left part of the graph". This got us on the path of finding the 2 line equations, and seeing what and why the slopes are what they are, and discussing point-slope form (the forgotten quiet nice guy in the class of line equations) vs. the ever-popular-player-guy "slope-intercept" form of the line equation. We set them up and discussed that those equations go on forever, so how do we show someone where it's restricted to. We then got it into an f(x) piecewise format and worked with finding f(32) and f(701) and describing what they mean.

Yea! For unexpected improvements to my as-yet-unwritten lesson plans.

Saturday, September 01, 2007

One Week Down

Even if I do no other exercise, that extra standing around from about 7:30am - 4:30pm HAS to burn at least 100 cal/hr. ... Okay, so that's really not my only major impression of the 1st week of school.

Ninety minutes goes by fast. I was concerned that I'd keep clock watching during our block schedule, but the only clock watching I was doing was to make sure I had enough time to do everything. In the middle of class for one set of the days I had the kids stand up, and we discussed social skills and going to parties in the future with your spouse where you didn't know anyone, and you had to meet strangers. So they had to walk around and find out the first name and the "earliest memory" that person has. I started that 1st class by calling it "cocktail hour", without thinking and then had to backtrack and say "without cocktails" after we giggled and then add "please don't tell your parents we had cocktail hour in class" (cough cough). I then had my brain kick in gear and continued calling it "meet and greet time".

For all the grumbling I was doing about block scheduling, I like the fact that on Wednesdays and Fridays, I'll mostly have taught everything the day before (save for BC calculus eventually), so that it's a less harried preparation day.

I think I've solved my homework problem. I didn't want to give double homework, since I think they'd leave it all until the last minute and not do a good job. I didn't want to give the same amount of homework as with a regular schedule, since I didn't think it'd be enough practice. So. On Mondays, our "C" day where all classes meet, I will hand out (10? 20?) cumulative-from-the-first-day math problems that will be due the following Monday. This will be in addition to their regular homework. That way, they'll get the extra practice and the extra "dipping" and review of old topics.

I also took a cue from the "Mathematics Teacher" magazine, and this past Friday assigned to my calculus classes: research who discovered calculus and find out 1 - 2 weird/interesting facts about him/her/them. (on hindsight, I should have had them cite their sources).

I think future weekend assignments for precal and cal may include finding out about various math-related jobs. I may give 1-3 types and divvy them up per class each time (civil engineer, architecht, physicist, etc.) and have them find out specifically what they do, schooling needed, average salary, who hires them, and anything else I can think of when I solidify it a bit more. This way throughout the course of the year, they'll be exposed to more possibilities than they may have thought of before. Maybe we'll make small posters and hang them in the halls.