Part 3 of The Standards for Mathematical Practice

Reason Abstractly and Quantitatively

A math teacher explains how well-designed materials can help students learn to deal with challenging math problems

“Problem solving.”

Be honest: haven’t you, at times, used these words to signal problems you would skip at the end of each section of your book? Don’t feel bad — we’ve all done it. It’s what we thought — or were told — was best. Problem solving is important though!

As educators, we want instructional materials that promote engagement in problem solving.  As students problem solve, they need the skills that were discussed in Standard for Mathematical Practice (SMP) 1 (make sense of problems and persevere in solving them), and also need to reason abstractly and quantitatively.  This abstract and quantitative reasoning is covered in SMP 2.

The two buzzwords when talking about SMP 2 are “contextualize” (taking the abstract mathematical representation and putting into context), and “decontextualize” (taking context and representing it abstractly).  Students need to move between these representations fluidly and use them to manipulate and understand the relationships between the quantities.  This idea relates primarily to abstract reasoning but we cannot forget quantitative reasoning.  While engaging in quantitative reasoning, students pay attention to the meaning of quantities they compute and also to the units involved.

Obviously, instructional materials for different grade levels will have some commonality in how opportunities to engage in SMP 2 will appear.  However, the complexity of the problems will increase as well as the depth at which students are expected to connect the quantitative and abstract reasoning.

As you can see in the grade 2 example below, students need to decontextualize the problem to write the equation 53 + 34 = __, showing abstract reasoning.  They also need to attend to the fact that the result they get, 87, actually means $87.

Sarah Galasso designed problem SMP 2Problem designed by the author.

As we look at the next example from grade 7, we see students engage in many of the same skills related to SMP 2 as they do in earlier grades.  Students are decontextualizing the problem, producing a symbolic representation, manipulating those symbols, and putting it back into context. We see that students are being asked to make sense of their abstract solution in context.  Additionally, we see the need to repeatedly move between the context and abstract representations.

Sarah Galasso problem SMP 2 from IMProblem from Illustrative Mathematics. Accessible here: https://www.illustrativemathematics.org/content-standards/7/RP/A/3/tasks/130

Looking at high school materials and SMP 2, we see students begin to deepen their understanding of various parameters and how changing those parameters changes the situation.   We can see an example of this below.

Sarah Galasso SMP 2 problem IMProblem from Illustrative Mathematics. Accessible here: https://www.illustrativemathematics.org/content-standards/HSF/LE/B/5/tasks/579

In looking at the above examples, you might recognize other math practices as well. Remember that the Standards for Mathematical Practice are not intended to be taught in isolation.  While you may see some questioning that helps students build their abilities in one specific math practice, you should also see opportunities to engage in multiple math practices simultaneously. This balance reflects how students will need to use their skills in real world scenarios.

Sarah Galasso designed problemProblem designed by the author.

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About the Author: Sarah Galasso began her career teaching high school mathematics in Anaheim, CA. While still a classroom teacher, Sarah has been transitioning into the world of professional learning. In this role, Sarah has been able to support multiple school districts in developing aligned curriculum and providing professional learning opportunities for teachers. Through her role within her school district and at other various organizations, Sarah has been able to work towards helping teachers build a better understanding of aligned instructional materials and assist teachers as they transition to a collaborative classroom. Sarah holds a bachelor’s degree in Mathematics with a minor in Chemistry from Whittier College, and is currently completing a master’s degree in Curriculum and Instruction. She is also a Master Scuba Diver Trainer and loves to go scuba diving in her free time.