Classifying shapes into a hierarchy is a 5th grade standard? Really?!

As I recently worked on correlating our materials to the newly released Common Core State Standards, I was surprised to find many of the topics we commonly associate with a high school geometry course placed throughout the standards for elementary grades.

I was surprised, but not shocked. In fact, I’ve believed for a long time that much of the geometry traditionally reserved for high school is prime material for middle school students. As long as the pedagogical approach supports students’ truly exploring geometry—through activities that allow them to draw, measure, construct, explore, and reason—it’s always seemed to me that topics such as congruence, similarity, transformations, properties of shapes, and classification systems are completely appropriate in middle school.
Now I’m not an expert on elementary education—in my 14 years of teaching I taught mostly high school students and some middle school students—but I do have a daughter who is now starting high school. So I tried to imagine her and her friends back when they were between 8 and 10 years old dealing with these standards:

Grade 3 (Geometry Standard 1) —

Understand that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals). Recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories.

Grade 4 (Geometry Standard 2) —

Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.

Grade 5 (Geometry Standards 3 and 4) —

Classify two-dimensional figures into categories based on their properties.

• Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category. For example, all rectangles have four right angles and squares are rectangles, so all squares have four right angles.

• Classify two-dimensional figures in a hierarchy based on properties.

At first, I thought to myself “This is crazy,” and joked with a colleague that our high school geometry book nails a 5th grade standard. But the more I immersed myself into the Common Core, the more I began to appreciate the substantive transformation of math education they propose. These are well thought out learning trajectories that combine age-appropriate pedagogical approaches with rigorous mathematics at younger ages. As the standards quoted above demonstrate, there is a conscious development of fundamental concepts over multiple years, not the usual snapshot of apparently random concepts listed for each grade level.

The trick then is in how to teach these standards at this level. Just taking the old high school geometry approach and dropping it down six or so grades would be pure torture for those little learners. But the Common Core emphasizes standards for mathematical practice, such as using appropriate tools strategically, both as overarching goals and as an integral component of specific content standards.

The key to success in adopting the Common Core is to not only change the grade level of when specific topics are taught, but also to thoroughly reevaluate the methods used at those grade levels, and to ensure that students are given the learning experiences that will deliver on the promise that these new standards engender.

12 thoughts on “Classifying shapes into a hierarchy is a 5th grade standard? Really?!”

    1. My classroom…it doesn’t mean that students have mastery of this standard by fifth grade, it simply means that it is introduced as a DOK 1 and 2 and differentiation begins as students move throughout the grades. It’s important to realize that standards often overlap in several grades, even from middle to high school. Their depth of knowledge increases as they move through their educational career and thus the level at which mastery becomes apparent is different for everyone.

      1. Hi Karli,

        This blog was written for teachers to reflect upon how they teach geometry in elementary and secondary schools. I’m sorry it doesn’t answer your question about how to create a hierarchy of shapes. I hope you’ve found other resources to help you.

  1. I am having difficulty locating the program/app that you are using in your video. We are an all Mac district and this app would be perfect for teaching this. Any suggestions on where to purchase?

    1. Hi Karli,

      This blog was written for teachers to reflect upon how they teach geometry in elementary and secondary schools. I’m sorry it doesn’t answer your question about how to create a hierarchy of shapes. I hope you’ve found other resources to help you.

  2. Good article, Andres. I am familiar with Leadership in SF. I currently teach at Mission High. great place to teach! We are adopting the common core this school year 2013-14

    I made illustrated posters for the common core, grades K-8. It took about a year. I am currently revamping them, starting with 5th grade math. The first time through, I mostly made illustrations of kids thinking about the mathematical concepts found in the standards. This time, I want to “show my work” a lot more, so to speak. I found this article because I was looking for some information on hierarchical classification of shapes. Good read!


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