Upon reading Authentic Tasks in a Standards-Based World by Edwards, Harper, and Cox, my inner battle begins to rage once more. My desire to take students to a deeper level in their learning is coupled with my desire to cover all of the standards. But how can I do both? The limiting factor is always this: time. Whether we like to admit it or not, the decisions we make as teachers are all too often dictated by time.

In the Authentic Tasks article, the authors use “The Meeting for Lunch Problem” as an exemplar. Students were given a very open ended question that asked where three people in different cities could meet for lunch such that each person had to travel the same distance to get there. Students were given the freedom to investigate and most of them successfully discovered that finding the circumcenter was indeed the method that would lead to a solution. If I am being honest with myself, this is where I would have likely ended the activity. After all, this lesson provided students with an application to a required standard. Check it off and move on, right? Not for Edwards, Harper, and Cox! They encouraged their students to ask probing questions and allowed them to take the activity in a new direction. When students discovered that in some triangles, the circumcenter was obviously out of the way for the three travelers and a foolish way to decide on a meeting place, they developed a revised goal in the “Meeting for Lunch” goal. Together with their teachers, they decided to find the meeting point that would result in the least total distance traveled for all three people involved. Even though this was uncharted territories (even for the teachers), they pressed on. After a lot of studying and a bit of research, they found that the “Fermat Point” would achieve their goal of finding the least total distance. Now, mind you, the Fermat Point is not mentioned anywhere in the Common Core State Standards (CCSS). Does that make studying it a waste of time? Absolutely not. These students applied their knowledge of the various circle centers in this problem as a lead-in to the critical thinking and problem solving that enabled them to extend their learning. They performed at a higher Depth of Knowledge level than they would have had they stopped after simply finding the preconceived circumcenter solution. The students took ownership of their learning.

Unfortunately, in the back of mind is still this issue of time. I wish I could push my students to a deep level of understanding with each and every topic, but I would simply run out minutes in the day and days in the school year. Even though I can’t turn every lesson into a three day mini-project in the computer lab, I must strive for balance. When I see a great learning opportunity to push my students, I must take it. Other times I must use my professional judgement to decide when that extra push isn’t quite as necessary. The most important thing is that my students are learning how to think at a deeper level on a regular basis.

Another highlight of the article for me was its quote from the Common Core State Standards for Mathematics (CCSSI 2010):

    These Standards do not dictate curriculum or teaching methods... [A] teacher might prefer to teach     a topic of his or her own choosing that leads, as a byproduct, to students reaching the standards         for topics A and B. (p. 5)

How refreshing! For some reason, this quote makes me feel better about going deeper with some standards than with others. The very institution that developed said standards is giving me permission to do it my way! I can hardly wait.

Professor Golden: I would appreciate feedback regarding the detail of my writing. Did I give enough detail to make my viewpoint known? Did I provide the right amount of information about the article to facilitate my reader’s understanding? Thanks!
 
It has been a couple of years since I taught geometry, and I only taught it for one year at that. Needless to say, my geometry skills are a little rusty. As a result, taking Modern Geometry (MTH 641) at Grand Valley State University this semester is proving to be a challenge, but in a way that I feel is helping me to become a better teacher. My professor has allowed the focus of the course to be on the teaching of geometry rather than purely geometry content, as all of the students are currently teaching mathematics at some level. This has given me the opportunity to analyze my approach and get down to the foundational building blocks of this fascinating branch of mathematics.

Over the past couple of weeks, we have been looking in detail at Euclid’s Elements. Reading the propositions in the mathematical language of Euclid’s day has challenged me to think about the true meaning of each statement. I cannot rely on my intuition or tidbits I memorized long ago. Rather, I feel it has placed me on an even playing field with my students. I actually feel as though I am learning it for the first time. One of our assignments this week was to take one of Euclid’s propositions from Book 3 (circles) and “modernize” it. I chose Propositions 22: The sum of opposite angles of quadrilaterals in circles equals two right angles. My version reads as follows: The sum of the measures of any pair of opposite angles in an inscribed quadrilateral equals 180 degrees. When I scrutinized the proof, one of Euclid’s methods of reasoning was easily recognizable to me. His proof said, “in any triangle the sum of the three angles equals two right angles.” Clearly two right angles is the same as 180 degrees, which indicates that he is referring to the modern-day Triangle Sum Theorem. His next justification was more of a puzzler. He claimed that two angles CAB and BDC were congruent because they were “in the same segment BADC.” This took some digging. When I looked back at Proposition 21, I found that this claim was in reference to the fact that a central angle subtended by two points is equal to twice the inscribed angle subtended by the same two points (paraphrased). By comparing two different inscribed angles subtended by the same two points, their measures were inferred to be the same. This, I finally realized, was an application of the Central Angle Theorem. From there I was able to finish my proof with ease. (See below.)

This assignment proved to be a great exercise! It took me out of my comfort zone and required genuine thinking and learning to take place. I have a renewed respect for historical mathematical texts, and I will look for a ways to have my high school students examine a piece or two sometime this year. It will also fit in great with the math department’s goal at my school to incorporate content literacy into the curriculum.

Professor Golden: I would love to hear some feedback from you with regards to some historical texts that might be the appropriate level for high school students, or even an idea for how to incorporate historical reading into an assignment or project. Thanks!


 
Last week my students saw and practiced their first method of proof in my freshman geometry class: Proof by Indirect Reasoning. I knew this would seem a strange concept to them. "If I think something is false, why would I say it is true?" was a question I knew I would be asked. In reality, I looked out at a sea of blank stares after showing the first example. Teaching how to write proofs takes time, though, and after a bit of practice it is finally starting to click.

For my initial lesson, I came up with an analogy to present the concept of indirect proof that I felt might help the students relate with this method of reasoning, however backwards it may seem. My advice to my students was this: Think like a lawyer.

Here is how our analogy went:

Me: Alright, who in the class looks especially guilty of a crime today?
       After many-a-suggestion, I decided to pick a student that would really play up the part so we could have some fun with it.
Me: What crime did Johnny* commit?
       *Name changed for student's privacy.
Johnny: I robbed a bank. 
       Said a little too quickly, I thought. ;)
Me: Okay. I'm a prosecutor in the courtroom. I think that Johnny robbed the bank, but he is pleading not guilty. This is how I will begin my proof: Let's assume that Johnny is innocent. Johnny, what is your alibi?
Johnny: I was on vacation.
Me: Were you on vacation the entire week of the crime?
Johnny: Yes.
Me: Okay, Johnny. But here's the thing. I have a security tape that shows you shopping here in town the night before the crime took place. You say you were on vacation. Unless you can be in two places at once, I'd say this is a contradiction!
       We than had a small sidebar conversation about the definition of a contradiction, which they had already written in their notes.
Me: This means my original assumption - that you were innocent - must be false. Therefore, you are guilty!

This was a fun way to introduce the topic of indirect proof so that my students could make a connection. Everyone has seen this method of reasoning used by a lawyer on TV, right? While it didn't make my students immediately become expert proof-writers, I did feel that it helped them to gain some insight and understanding into how and why this method of proof is used. It also supports the stance of Eric Knuth in his article, Proof as a Tool for Learning Mathematics. He asserts that proofs should not only show that something is true, but also why it is true. This will enable them to better comprehend the underlying mathematics. After all, if students don't understand the why, have we really done our job?

If anyone else has some analogies or strategies for teaching a particular method of proof, I'd love to hear about it in the comments section!




 
Learning about the Van Hiele levels in my grad class right at the start of the school year once again got me thinking about how I can assist my high school math students to perform at a higher level. With the implementation of Common Core and the looming SBAC assessments, math teachers are feeling the pressure now more than ever to ensure that our students are able to think critically, reason logically, and problem solve effectively. Basic comprehension and limited mathematical skills will in no way be enough when it comes time for mandated testing (nor should it!). I am realizing quickly that not only must we work harder, we also have to work smarter. This means understanding how our students learn.

The concept of Van Hiele levels follows the common educational theme of progressive levels of thinking. What makes it especially useful is that it is specific to geometry! Bloom’s Taxonomy, which seemed to be a hot topic during my undergraduate career, includes the following levels: Remembering, Understanding, Applying, Analyzing, Evaluating, and Creating. The more recent focus since our transition to the Common Core has been on Webb’s Depth of Knowledge (DOK), which includes Recall (level one), Skill/Concept (level two), Strategic Thinking (level three), and Extended Thinking (level four). Both models can be applied to all subject areas, and both mean basically the same thing. Now consider the Van Hiele levels: Visualization, Analysis, Abstraction, Deduction, and Rigor (as outlined in Marguerite Mason’s article). These levels can easily and directly be related to the Geometry Common Core State Standards.

Having Van Hiele in mind will help me to apply Webb’s DOK in my Geometry classes this year and to identify the levels at which my students are performing. I have only taught Geometry once prior to this year (as a sophomore-level course), and in my experience most students came in with Visualization and Analysis skills. Bright students picked up Abstraction, but Deduction was a struggle for almost all of my students. This year, my Geometry students will primarily be freshman. They will not have taken Algebra 1 yet, and I am interested to see if that impacts their capabilities or if my observations remain largely the same. I am hoping to develop strategies and activities that will push my students to use Abstraction and Deduction on a regular basis, so that eventually it comes naturally to them.