In this unit students extend the understanding of attributes—e.g. orientation, size, and number of sides—they learned in Kindergarten to distinguish between defining attributes and nondefining attributes. Students need to explore various examples in different ways so that their experience with shapes are not limited to single examples(e.g.if a student has only worked with equilateral triangles, it may be difficult for them to develop more general understandings of triangles).
Key Concepts:
 Shapes have both defining (triangles are closed threesided shapes) and nondefining (color, size, orientation) attributes.
Prior Knowledge Needed:
 Correctly name shapes regardless of their orientation or overall size (K.G.2)
 Identify shapes as twodimensional (i.e., lying in a plane, “flat”) or threedimensional (i.e., “solid”) (K.G.3)
 Analyze and compare two and threedimensional shapes, in different sizes and orientations, using informal language to describe their similarities, differences, parts (e.g., number of sides and vertices/”corners”) and other attributes (e.g., having sides of equal length) (K.G.4)
Units on the Horizon:
 Build and draw shapes to possess defining attributes; (Grade 1, Unit 12; 1.G.A.1).
 Compose twodimensional shapes or threedimensional shapes to create a composite shape, and compose new shapes from the composite shape; (Grade 1, Unit 12; 1.G.A.2)
 Partition circles and rectangles into two and four equal shares, describe the shares using the words halves, fourths, quarters; (Grade 1, Unit 17; 1.G.A.3)
Lessons

Lesson objective: Explore the characteristics that define different shapes and the names of those shapes. Students bring prior knowledge of naming shapes regardless of their orientations or overall size from (K.G.2). This prior knowledge is extended to ...

Lesson objective: Reason to differentiate between geometrically defining attributes and nondefining attributes. This lesson helps to extend understanding of attributes. Students will describe in their own words why a shape belongs to a given category. ...

Lesson objective: Explore the characteristics that define different shapes and the names of those shapes. Students bring prior knowledge of naming shapes regardless of their orientations or overall size from (K.G.2). This prior knowledge is extended to ...

Lesson objective: Reason to differentiate between geometrically defining attributes and nondefining attributes. This lesson helps to extend understanding of attributes. Students will discuss nondefining attributes such as color, shape, and size of an ...

Lesson objective: Sort and classify objects using defining and nondefining attributes; identify and name sorting rules. This lesson helps to extend understanding of attributes. Students will sort and classify objects using nondefining attributes such ...