Saturday 13 December 2014

Proportional Reasoning

This past month has been extremely busy and therefore my teaching partners and I decided to put a pause on our Number Talks until we have time to coordinate some next steps for our class in the New Year. In the meantime, we have joined our school board's Collaborative Inquiry in Mathematics and began another math journey into something called proportional reasoning.

I was first introduced to proportional reasoning in my Math AQ course this year, and at first glance, I found the concept seemed very logical and easy to understand since it just seemed to be a part of everyday life. I knew I had never heard the term before but it seemed as if we had always been teaching it anyway. My impression was that it was about problem-solving and as long as we provided students with real-life problems then they would develop their proportional reasoning. 

My thinking:
"What does this have to do with proportional reasoning?
Prior to our first session for the collaborative inquiry, we were asked to provide students with a task from a list and to bring in some student work samples. The tasks were all aimed at helping students develop proportional reasoning. We chose one about showing the number 10 in various ways since it seemed to be the most basic task. We began representing the number 5 for the first week and then 10 the following week. I was very unsure how this related to proportional reasoning, since I thought proportional reasoning only had to do with presenting real-life problems.

A few weeks later, as several of the primary teachers from my school board gathered for our first Collaborative Math Inquiry session, I realised proportional reasoning was not so easy to explain and not just developed by giving students real-life problems. As we discussed the idea and our understandings of it and read some supporting documents, I started to confuse it with the idea of subitizing. But after a full day's workshop with some very interesting discussions, videos, and attempts at solving problems on our own, I have a much clearer picture of the concept.  

In my own words, proportional reasoning is a way of thinking about problems and comparing amounts and their relationships in relative versus absolute terms. It involves solving real-life problems and the capacity to subitize is a precursor to looking at those real-life problems using proportional reasoning. Therefore, developing students' ability to subitize actually is a way of proportional reasoning in and of itself. And the task we chose - representing the number 10 in various ways -  also can involve subitizing, thus the connection with proportional reasoning. 

We were also given an excellent resource to aide in our understanding of proportional reasoning. I highly recommend this monograph: Paying Attention to Proportional Reasoning: Support Document for Paying Attention to Mathematical Education (2012). December has been an incredibly busy month and amid all the items on my to-do lists, reading that resource, I must say, was not my number one priority. I was quite frustrated by some unexpected financial “to-do’s” that suddenly were thrown at me in December; but to my surprise, my financial “to-do’s” not only involved many mathematical operations but an incredible amount of proportional reasoning. When dealing with anything financial, it is obvious how mathematics plays a role but I started to realise proportional reasoning seems to permeate more areas in my life than I had previously thought.

The first real-life situation that comes to my mind in which proportional reasoning is involved would be comparing prices at the grocery store. Often we must not only consider the prices and quantities but in order to properly compare we must use proportional reasoning to decide whether the prices are even comparable and multiplicative thinking in order to calculate how much the item is relative to the other. Our comparison must be based on similar quantities. Comparing prices is an example of an authentic situation that occurs more regularly in our adult lives. Other examples include: using recipes and cutting them in half/doubling them, dividing up pizza among a group of friends, and calculating the temperature from Fahrenheit to Celsius or vice versa. In order to prepare students to solve these everyday problems, it is necessary to help students learn how to use proportional reasoning and provide them with these types of authentic problems at their own level of understanding and interests.

I just had to share this funny  article  I found while searching for
some images about sharing pizza
!
After dealing with my finances, I finally found some time to look over the document and contemplate just how complex proportional reasoning can be. “Proportional reasoning is a complex way of thinking and its development is more web-like than linear. Students do not think through an identical concept in exactly the same way so there are myriad possibilities at play when developing the ability to reason proportionally” (p. 4 Paying Attention to Proportional Reasoning.) It is very interesting to note how I was feeling when tackling my own real-life problem that involved proportional reasoning. Mostly, I was frustrated that it was consuming an incredible amount of my time when I needed to put that time into writing this reflection. The task was also very complex. I had to review and compare amounts and make many calculations to verify if they were correct. On top of all this, I had to explain my thinking and I realised that was one of the most difficult parts. I think it was so difficult because I was trying to explain my proportional reasoning which involved many numbers and operations and as stated before, there is not one way of thinking about a particular problem. My explanation may not make sense to others. Thus we must allow students to present multiple ways of thinking about problems just as we are doing through our Number Talks.

I must note here, before moving on, a memory from my childhood. When I was about 10 years old I can recall having some math homework that was a bit tricky and my dad was attempting to help me out and trying to convince me to try to use his method. I was very much convinced I needed to use the formula and strategies my teacher taught me in class and had so much trouble looking at the problem from another perspective. I understand now that my dad was trying to get me to look at the big picture and use proportional reasoning. I clearly was not in the mindset that math problems could be solved in different ways and not able to apply proportional reasoning in solving my math homework. Since the concept of proportional reasoning seems like a relatively new term, looking back on my mathematical education from the perspective of an educator, I now see how it is very important for students’ math education from an early age. The Paying Attention to Proportional Reasoning document states: “Although the Ontario curriculum documents for mathematics do not reference the term proportional relationships until Grade 5, activities in the primary grades support the development of proportional reasoning” (p. 3). Since proportional reasoning is so complex, it is not explicitly in our Ontario Math curriculum until the later grades; however as the document addresses, it is important to understand it as an educator and provide students with opportunities to develop it, even at a young age.

The Paying Attention to Proportional Reasoning support document divided the complexity of our thinking into different concepts which we use in a “web-like nature”: understanding rational numbers, multiplicative reasoning, relative thinking, understanding quantities and change, spatial reasoning, measuring, linear models, area, volume, unitizing, comparing quantities and change, scaling up and down, and partitioning (p.4). The one type of thinking that drew my attention was unitizing and spatial  reasoning. As the document notes: “Unitizing is the basis for multiplication and our place value system which requires us to see ten units as one ten and one hundred units as ten tens… this is complex since unitizing ten things as one thing almost negates children<s original understanding of number… Spatial visualization allows the student to understand the unit as equal intervals of distance. This is exactly what we were working on in both our Number Talks and in the task involving representing 10 in different ways.

Originally, when I joined the Collaborative Math Inquiry, I thought that the tasks would take us in a different direction than our Number Talks. But as I embark on my own math learning journey it is exciting to develop a greater understanding of the big picture and
see the interconnections among the mathematical concepts I am teaching. I am really eager to be a part of this school board inquiry and further explore how to develop primary students’ proportional reasoning as well as improve their mindset, communication and number sense skills.

Other Proportional Reasoning Resources:

Another ministry document that has samples of questions and other suggested resources:
Continuum and Connections: Big Ideas and Proportional Reasoning K-12

A colleague of mine was also searching for Kindergarten resources related to proportional reasoning and found the following document. I have not yet had a chance to read it but it looks quite useful. The document is long but you will find a section in the contents on proportional reasoning. 


During the first session of our Collaborative Math Inquiry, each Grade team got together to discuss what area we thought the students needed most attention/improvement.  Our Kindergarten Team was able to group our ideas into three categories which we prioritized below:


1) Mindset
2) Communication
3) Number Sense

I found these resources for mindset and communication on a document we got at the first session:



Maximizing Student Mathematical Learning in the Early Years ((Capacity Building Series Special Edition #22, September 2011).