Tuesday, May 5, 2015

The Unit Circle of Life


Our math department is divided. Some like teaching the trig ratios with the Unit Circle, some don't. Since I hate  conflict, I teach both methods--one where students will draw a triangle in a quadrant and use what they know about 30-60-90 or 45-45-90 triangles to solve, and one where they learn the first quadrant of the unit circle and then reflect into other quadrants to get the answer.

For years, I have assigned a unit circle project, where students design a unit circle to wear or bring with them all day...the crazier, the better. I give bonus points to the top 3. Some of my favorites have involved printer tattoos that students wear, Shrinky Dink jewelry, Unit Circle Togas...so many more...

But one day earlier in the year I came across Unit Circle Art, a blog by Miss Rudolph. I loved her guidelines and rubric, and I used it in my Pre-Calculus and Algebra 2 Honors classes, and I have never been more pleased with the results. So this year, students were told not to use pre-made circles...that was a game changer. In the past, I have gotten some very lame projects where students cut out unit circles and paste them on circular shapes. I also said that they could not use the site http://www.embeddedmath.com to have a pre-made circle. So students worked really hard (for the most part...and if not, their grades suffered.) Here are some of the best ones.

Coolest thing ever!!

The Unit Circle of Life!

The rules were: Do not use a circle to begin with, but you may draw a circle. You must include degrees, radians, sine, cosine, and tangent of each special angle. You may not use a pre-drawn unit circle. According to the blog mentioned before which I pinned on Pinterest here: unit circle project, and I used Miss Rudolph's rubric exactly.

I have been fortunate enough to have a new classroom since spring break, where 3 walls are wallpapered with white board paper. I tried to think how I could do something different after teaching the unit circle that would involve students going to the board. On the fly (usually the best way it works--organically), I asked students to go to the board in pairs, each having a different marker. Here were the directions:

partner 1: draw a circle
partner 2: draw the lines
partner 1: label quadrant 1 in degrees
partner 2: label quadrant 2 in degrees
continue for quadrants 3 and 4 alternating, and then continue for radians, (cosx,sinx) and tanx

The kids were definitely talking it through...it was a million times better than when I have had them fill in the unit circle on their own in the past...they loved drawing it on the board, and they helped each other and talked it out. Students that were confused had a partner to help them. If a pair was stuck, they could look at what another pair was doing.

Geek of the Week competition

My students love vying for Geek of the Week, and they asked to see who could draw the unit circle fastest...of course we had to use the Theme from Rocky...I got this idea from a blog but I can't find it...if you know where I got it from, please let me know so I can give credit to the owner!


Mu Alpha Theta States was so much fun...the poster competition was "Math and Movies." Seven girls worked so hard to create this poster...some stayed up all night, in fact! We did not win, but they definitely won in my eyes! It's a combination of Mean Girls and Good Will Hunting and DaVinci Code.


I was told by family members that this was the best dessert ever, so here is the recipe of Flourless Chocolate Cake by King Arthur...very rich and decadent!