Geometry Curriculum Track

The K – 5 Geometry Lessons consist of a complete set of lessons aligned to the Common Core State Standards (CCSS) for mathematics. This comprehensive set of lessons addresses the entire geometry domain from kindergarten through fifth grade. These lessons were written in response to a summary of the research on the development of mathematical thinking in children by Clements and Sarama (2009). In their book, Learning and Teaching Early Math: The Learning Trajectories Approach, Clements and Sarama (2009) describe the learning trajectories for the development of shape in children. To develop a rich and robust understanding of the defining attributes of two- and three-dimensional shapes, Clements and Sarama (2009) recommend incorporating the following four features in the geometry curriculum:

  1. Provide numerous and varied examples of shapes as well as nonexamples to develop a finer understanding of the defining attributes of each shape.
  2. Encourage students to describe shapes using language that references their defining attributes.
  3. Expose students to a wide variety of shape classes and, to the extent possible, relationships among classes.
  4. Challenge students with a wide variety of geometric activities.

The K – 5 Geometry Lessons were developed to reflect these recommendations. Each of the basic shape kits includes conventional examples of shapes from various shape classes (exemplars), a number of variations within each shape class (variants), and shapes that might be mistaken for shapes within a class (distractors). For example, the Basic Shapes: Triangle Kit contains exemplars such as an equilateral and an acute isosceles triangle, variants such as an acute scalene and an obtuse isosceles triangle, and distractors such as a sector and a chevron. Throughout the lessons, students are asked to distinguish between examples and nonexamples of shapes and justify their decisions by appealing to the defining attributes of the shape class (e.g., the defining attributes of a triangle are that it is a closed shape with three straight sides). The K – 5 Geometry Lessons incorporate a variety of pedagogical approaches (e.g., whole group discussions, engaging group and partner activities, active student participation, assessment opportunities, and self-assessment exercises) and reflect the Standards for Mathematical Practice advocated by the Common Core State Standards Initiative.

The kits developed for these lessons include the following:


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