Day 155 & 156: The Triplets of Cellville

I chose this Mathalicious lesson because we have not used circles enough in my geometry classes. We stared the school year with constructions, but haven’t used them much this semester and I wanted them to recall and extend prior learning. I also wanted students to gain more experience modeling real world scenario’s with mathematics & I thought this task would be engaging do to it’s relevance to students lives.  I started off showing the introductory video clip which is a news story of a woman explaining how photos taken with a cell phone include GPS data and how your cell phone records your location. I was surprised that ALL of my geometry students were furious at this video. They thought this lady was dumb for being surprised because “…everybody knows that you can turn on and off the location settings on your phone!” one student argued that if this woman in this video was her mother, she would be furious at her for being so clueless. It was great because it got very intense, and I had no idea how savvy students are with their cell phones. After this discussion died down students inevitably asked: “Wait, what are we doing today? Are we learning how to stalk people with their phones?” and “Mrs B, you are so weird.” Also “This is going to be awesome!” They were hooked.

I don’t want to describe the entire lesson in too much detail because I want you to support Mathalicious and their quality activities, but students constructed circles on a map to determine possible locations of a person in relation to a few cell towers. The lesson also discussed coverage vs locate-ability and students had to use estimation & area formulas in order to draw conclusions and also to determine and justify where they would add a cell tower in a city if they were in charge of making the decision. The only thing I would change for next school year is that I would modify the lesson to use our town and cell tower locations locally to make this more relevant and less hypothetical. Students were engaged and it was a good way to use student interest and incorporate modeling at the end of a school year when motivation is typically pretty low.

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Day 85: Viewmongus Awesomesauce

Today was so fun! We did a warm up reviewing Pythagorean theorem, then as a class, we worked through finding the dimensions of the 55″ television at the beginning of act 2.


Students then worked in small groups to answer and discuss whether an 80″ TV is really more then double the area of a 55″ TV.  There was struggle, success, frustration, persistence, debate. Standards of mathematical practice abound!  Ahh, it was beautiful.

I had a few students who found a more efficient methods for finding the area of each TV:

The student below found the proportional increase from a 55″ to an 80″ and just multiplied the side lengths by the same ratio:

20140115-134412.jpgThis student calculated the area of each “square” in a 16 x 9 TV, then multiplied it by 144, saving him the effort of finding the length of each side and then the area:


I love how students develop such smart methods when left to their own devices. Its sad to think of all of the times I’ve stifled that creativity by showing them just one method to solve a problem, instead of equipping students with tools and a good understanding of a problem and allowing them to use the tools as they see fit.

Day 84: starting Viewmongus

This was rough. I noticed that when I get frustrated, I push students harder & talk more, meaning that they learn less & I get exhausted & more frustrated. They did well with act 1, but then it fell apart. I need to shut up and give them time to think and trust that they will get there. Why is it so obvious as I post this, but it wasn’t an hour ago?


Day 69: Starting Transformations unit: Face off by Mathalicious

Warning: this post makes a lot more sense if you are looking at the Mathalicious lesson, Face Off.

I worked through this activity prior to the start of class and thought that the geogebra files may impede students understanding of what they are measuring & why. I also knew we would not get to this until day 2 of the lesson, so I wanted to see how day 1 unfolded. Students seemed to really respond to faces. It got serious when we started looking at Beyonce’s face. I had no idea she was so polarizing!

Students had some great strategies for drawing the right side of each image in act 1. One student traced the left side using patty paper, flipped the patty paper to the right side and scratched it with her fingernail, which transferred the image to the right side. She then went over it in pencil and it was flawless! It was hard to not be helpful, but I consider it promising that students keep expressing frustration that I am not giving them enough direction or telling them what to do., but then they proceed to do a great job.

Many students flipped past the second part of act 1 and started jumping ahead while their peers were finishing their drawings. I had to tell them that today we are only looking at act 1, and I am giving them plenty of time because I expect them to do quality work. I made up a story to make it more personal: Demitiri made the drawing on the left and Kayla made the one on the right. I think Kayla’s looks better, but not perfect so I’m going to give her a B, and Demitri should get an F because that just looks bad to me. Arguments ensued. Measurements and rulers came out, it was a good discussion on how to fairly measure imperfections in symmetry.


Next we used geogebra, because measuring was getting tedious, and completed the celebrity analysis. My only complaint with the geogebra file is that the titles on the right side points were movable, so some students moved the titles instead of the points, resulting in inaccurate measurements and lots of cursing & frustration on their part. Some of my classes got to the Obama part, but not all of them.

This lesson went well, but I did not feel like it ended with any real conclusion. The students were engaged, and they developed mathematical systems of measurement, which I think is much more important than being able to repeat a process. I will definitely do this again



Day 67: Mathalicious project choice

I let students choose between “Cover me” & “Chain Effect” I gave as little direction as I could tolerate & they worked hard on it today. We only worked on it in class for 1 day. They were shocked that I allowed them to use their cell phones to call local pizzarias & find out their pricing schemes. Some students used a computer to create graphs using Desmos. Another student was angry because she “never gets toppings, so this does not matter to her.” I will check on their progress throughout the week. It is due on Friday. I’ll let you know how it goes.