Friday, November 28, 2014

How did the teacher organize the turkey-cost discussion?

My preservice teachers have reached stage four, Sequencing, of the Five Practices (see previous posts for Anticipating, Monitoring, and Selecting). Because these teachers have no direct experience facilitating a discussion involving students reflecting on their mathematical thinking, we return to the third-grade class and watch a video of how the teacher Sequences the work of the students on the turkey-cost problem. I ask the future educators to watch the consolidating conversation and hypothesize why the teacher decided to order the student-work the way she did.
All images are from New Perspectives on Learning
used with the permission of the authors

Emma and Emma take the $1.25/pound price and start with a friendlier number - $1 per pound. If that were the price, then the 24 pound turkey would cost $24. But they recognize they need another twenty-four $0.25 to find the total costs. So they count by 25s, keeping track of how many 25s they have counted underneath. They find they need another $6 for a total cost of $30.

Harry and Ese use a similar strategy of breaking the price per pound into a dollar and a quarter. However, instead of counting by 25s, they gather the quarters in groups of four. Each group of four quarters is a dollar. There are six groups. Therefore, $6 must be added to $24 to get the total cost of $30.

The next pair, Nellie and Nate, also start by taking off the 25 cents to get an initial cost of $24. Then they group the quarters, but they do it differently than Harry and Ese. Instead of showing "pictures" of quarters, they use a table to represent the relationship between pounds and dollars at $0.25 per pound. The table shows that 24 pounds requires an extra $6. Again, the total cost is $30.

Finally, Suzanne and Rose share a unique strategy that does not break up the $1.25. They know that "4 pounds is 5.00" and use this to jump by 5s on the open number line. There are six jumps because there are six 4s in 24 pounds. Although they use a different approach, Suzanne and Rose also find the cost to be "30 $ in all!"

After observing the Sequence of approaches, the preservice teachers offer their hypotheses about why the teacher put the student-work in this particular order. Some suggest it might have progressed from "most popular" to "most unique." Others think it was based on increasingly sophisticated structures. A few wonder if it might be related to the different representations being used.

Why do you think the teacher ordered the work in this way? And where do you think the teacher goes next to complete the last Five Practices stage, Connecting? As always, your participation in the comments is appreciated.

Wednesday, November 26, 2014

Who should share their turkey-cost solutions?

All images are from New Perspectives on Learning
used with the permission of the authors
In preparing future educators to facilitate productive math lessons, we provide opportunities for them to apply the Five Practices to problems like the one shown here. Teachers began (in the first post of this series) by identifying a Standards for Mathematical Practice (SMP) to focus on and Anticipating student solution strategies related to this SMP. Next (in the second post), they watched video of third-graders solving the problem in order to Monitor their efforts and compare them to the Anticipated responses. The teachers were also given copies of the students' work to examine. Teachers use this work to begin the process of Selecting who might share during a whole class discussion.

For example, the teachers focusing on SMP 5 might Select these students to share because they all used the open number line as a tool.
The discussion could revolve around how this tool was used appropriately and strategically.

Another group of teachers, focusing on precision could Select the work of the third-graders shown below since they seemed to arrive at different answers.
The class could work together to determine what question each pair of students was answering and how to move toward a correct solution.

Finally, teachers wanting to focus on structure might Select these four student-pairs.
This work included different ways students used the structure of money (decimals) to arrive at a solution.

By strategically Selecting student work to share, a teacher does not leave the  ensuing discussion to the vagaries of volunteers. Consequently, the resulting classroom conversations becomes more purposeful and productive. But first, the teacher must apply another of the Five Practices - number four, Sequencing

How might a teacher organize the Selected student-work for each SMP in order to maximum learning and why?

Tuesday, November 25, 2014

How did those third-graders determine the turkey's cost?

All images are from New Perspectives on Learning
used with the permission of the authors
Having anticipated third-graders' thinking for the scenario provided above (the first of the Five Practices which was attended to in the first post in this series), my preservice elementary teachers are ready to engage in the next Practice - Monitoring students' thinking. Unfortunately, the university has yet to meet my request for a lab school which means that elementary-aged children are in short supply in my classroom. Given my desire to create as authentic experience as possible for my teachers, this creates a problem.

Luckily, Dr. Catherine Fosnot and her colleagues have gathered classroom videos and student-work from elementary kids working on problems from their Context for Learning Mathematics (Fosnot et. al.) series (including from the turkey cost lesson). While it's not the same as monitoring actual students, it does represent the same experiences inservice teachers might have in Professional Development (PD) sessions using Dr. Fosnot's materials.

This PD involves helping teachers to develop phronesis. "Phronesis is situation-specific knowledge related to the context in which it is used—in this case, the process of teaching and learning." (from p. 147 of Young Mathematicians at Work: Constructing Multiplication and Division) By watching the video and examining the students' work, teachers are able to observe an authentic lesson and reflect on the teaching moves that support students who are immersed in doing mathematics.

The preservice teachers in my class watch the video and observe the students finding the turkey cost. Just as many of them predicted, the third-graders are splitting the $1.25 per pound into a dollar and a quarter. Students' papers (like the one on the right) show that they understand the 24-pound turkey will cost $24 plus 24 quarters. Pairs of students use a variety of approaches to determine the total cost of the turkey. As my teachers review the third-graders' efforts, the teachers move toward the next phase of the Five Practices - Selecting students to share their work based on the Standards for Mathematical Practice (SMP) selected at the beginning of this process. 

We will continue this work in the next post. But first, which SMPs would you say the work of Emma and Emma highlights?

Thursday, November 13, 2014

How much is that turkey in the window?

Disclaimer: I receive no financial benefit for my endorsement of the Context for Learning Mathematics (CFLM - Fosnot et. al.) curricula or the associated professional development resources shared in this series.
In my efforts to make my classes for preservice elementary teachers more accurately reflect the work of teachers, I try to craft my lessons as professional development sessions. We spend a significant amount of our time applying the Five Practices for Orchestrating Discussions to activities from established K-6 mathematics curricula. Recently, we used a lesson from CFLM's The Big Dinner unit in anticipation of Thanksgiving.

From Professional Development Resources
used with permission of author
This introductory lesson asks students to find the cost of buying a 24 pound turkey. My teachers start by selecting a Standard for Mathematical Practice (SMP) as a goal for the lesson. (We could also look at content goals, but these teachers need more practice with the SMPs.) Having chosen a goal, the teachers begin applying the First Practice: anticipating possible student responses associated with the goal. The students in this scenario are third graders who are unlikely to use the standard algorithm for multiplying decimals.

Many of the teachers anticipate that the students will break the $1.25 into dollars and cents. For the teachers who identify "Look for and make use of structure" as their SMP goal, this prediction seems reasonable. Some of the teachers consider the models and tools (SMP 4 and 5) students will use to solve the problem. Other teachers, who are attending to precision (SMP 6), wonder where students might make mistakes in their computation. Nearly all the teachers are interested in the different strategies the students will use to solve the problem.

Before we move on to the Second Practice, monitoring students' work, I want to give you an opportunity to add the SMP you would choose to focus on for this problem and possible student responses you might anticipate. As always, please add your contributions to the comments.

In the next post, I will explain how preservice teachers can carry out the remain Practices of Orchestrating Discussions even though they are not actually in an elementary school classroom. 

Sunday, November 9, 2014

What is this craziness?

From 1075 KZL Facebook Page
If we are to believe memes like this, the math currently being taught in schools has never been so meaningless. What exactly is this craziness? According to a recent NBC News story, it involves using number lines.

I understand that this approach can be confusing to adults who were taught an algorithm without really understanding why it works. Unfortunately, many of these adults have forgotten how memorizing rules without reasons made them feel as a kid.

As students, we wanted our mathematical efforts to make sense. But instead, we got little ditties like, "Mine is not to question why, just invert and multiply." So we made up that doing math simply meant following certain rules given by some authority.

It is reasonable that adults who grew up with this view of mathematics might be confused by instructional approaches meant to foster the development of mathematical understanding rather than rote rules. However, my primary concern is the confusion of the kids not the adults. To do otherwise is not only crazy, it is insane.