MA.2.GR.1.2

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Categorize two-dimensional figures based on the number and length of sides, number of vertices, whether they are closed or not and whether the edges are curved or straight.

Clarifications

Clarification 1: Instruction focuses on using formal and informal language to describe defining attributes when categorizing.
General Information
Subject Area: Mathematics (B.E.S.T.)
Grade: 2
Strand: Geometric Reasoning
Standard: Identify and analyze two-dimensional figures and identify lines of symmetry.
Date Adopted or Revised: 08/20
Status: State Board Approved

Benchmark Instructional Guide

Connecting Benchmarks/Horizontal Alignment

 

Terms from the K-12 Glossary

  • Hexagon
  • Rectangle
  • Regular polygon 
  • Octagon 
  • Pentagon 
  • Triangle 
  • Square 
  • Polygon

 

Vertical Alignment

Previous Benchmarks

 

Next Benchmarks

 

Purpose and Instructional Strategies

The purpose of this benchmark is for students to work specifically with two-dimensional figures to categorize them based on their attributes. 
  • Instruction includes a variety of examples and non-examples which lack defining attributes. 
  • Instruction includes the understanding that some figures may share the attributes of another figure, possibly creating subcategories. For example, squares form a subcategory of rectangles. 
  • Instruction is not limited to polygons.

 

Common Misconceptions or Errors

  • Students may not realize figures can be categorized in more than one way. 
  • Students may have difficulty categorizing figures that are considered irregular.

 

Strategies to Support Tiered Instruction

  • Teacher may refer to “Collect and Display” activity from 2.GR.1.1 and replicate for this benchmark activity.
  • Teacher provides students with a collection of two-dimensional shapes, including triangles, rectangles, squares, pentagons, hexagons, and octagons as well as some non-examples, to do the following activities:
    • Teacher, using only regular plane figures, asks students to sort them by size, shape or color. If needed, the teacher can explicitly teach that shapes can be sorted in different ways. Call attention to the words used during each sort to help students make connections between their informal language and the formal content vocabulary (see “Collect and Display” math language routine above).
  • Teacher provides a set of plane shapes, including irregular polygons, and asks students to sort them any way they can but that they must use all the figures provided.
    • Teacher asks, “How did you decide to sort them that way?” or “How did you know which shape belongs in this group?”, calling attention to the student language used and its connection to the formal content language.

Instructional Tasks

Instructional Task 1 (MTR.2.1) 

Provide students with isometric dot paper. Read aloud and describe a two-dimensional figure by naming the attributes. 
  • Part A. Draw the figures described. Once the figures are drawn, cut and place their figures under the appropriate provided categories in the table below. Some figures may fit in multiple categories, so encourage students to choose different categories to place their figures in, have students. 
  • Part B. Discuss why you chose the different categories. Help students understand that some figures may not fit into any categories during this task (e.g., figures with curved sides).

 

Instructional Items

Instructional Item 1 

Tina builds the following figures and categorizes them both as hexagons. Is she correct? Explain why or why not. 

 

*The strategies, tasks and items included in the B1G-M are examples and should not be considered comprehensive.

Related Courses

This benchmark is part of these courses.
5012040: Grade Two Mathematics (Specifically in versions: 2014 - 2015, 2015 - 2022, 2022 - 2024, 2024 and beyond (current))
7712030: Access Mathematics Grade 2 (Specifically in versions: 2014 - 2015, 2015 - 2018, 2018 - 2022, 2022 and beyond (current))
5012005: Foundational Skills in Mathematics K-2 (Specifically in versions: 2019 - 2022, 2022 - 2024, 2024 and beyond (current))

Related Access Points

Alternate version of this benchmark for students with significant cognitive disabilities.
MA.2.GR.1.AP.2: Sort two-dimensional figures based on the number of sides, number of vertices, whether they are closed or open and whether the sides are curved or straight.

Related Resources

Vetted resources educators can use to teach the concepts and skills in this benchmark.

Formative Assessment

Identifying Polygons:

Students are asked to describe attributes shared by three shapes and to identify a larger category into which these shapes can be placed.

Type: Formative Assessment

Lesson Plans

Exploring Machine Learning to Train an AI Model:

Students will explore Artificial Intelligence (AI) and Machine Learning (ML) and pretrain a model to recognize and identify objects, including geometric shapes and aircraft. They will used unplugged activities to mimic sorting and classification of the objects using their prior knowledge and then make connections to human learning and Machine Learning. Students will then problem solve and propose solutions using an iterative process to improve the ML model to better recognize the objects. This lesson is an integrated Computer Science, Science and Math lesson designed for students in K-2 to apply math and science content knowledge while exploring and using computational thinking like people in Computer Science careers do.

Type: Lesson Plan

Capitol Geometry - Lesson 2:

In this lesson, students will continue learning about the history of the Florida State Capitol building, through a grade-level appropriate reading. They will then be provided with a diagram of the glass dome from the Old Capitol. After direct instruction on categorizing two-dimensional figures based on defining attributes, they will use the diagram of the glass dome and categorize the figures.

This is lesson 2 of 3 in a mini-unit integrating civics and math.

Type: Lesson Plan

Attributes of 2D Figures:

In this lesson, students will identify and categorize pentagons, hexagons, and octagons based on defining attributes. Students will sort based on closed, straight sides, number of sides, and number of vertices.

Type: Lesson Plan

Perspectives Video: Teaching Idea

Double Bubble Diagram to Compare Math Concepts:

Unlock an effective teaching strategy for helping students make connections in mathematics using the Double Bubble Diagram in this Teacher Perspectives video for educators.

Type: Perspectives Video: Teaching Idea

Teaching Idea

An Introduction To Quadrilaterals:

This lesson is designed to introduce students to quadrilaterals and the terms and properties associated with quadrilaterals. This lesson provides links to discussions and activities related to quadrilaterals as well as suggested ways to integrate them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

Type: Teaching Idea

MFAS Formative Assessments

Identifying Polygons:

Students are asked to describe attributes shared by three shapes and to identify a larger category into which these shapes can be placed.

Student Resources

Vetted resources students can use to learn the concepts and skills in this benchmark.

Parent Resources

Vetted resources caregivers can use to help students learn the concepts and skills in this benchmark.