In this unit, students will explore partitioning circles and rectangles into either two equalsized shares (halves) or four equalsized shares (quarters/fourths). This extends student knowledge of defining characteristics of shapes as well as how to compose new shapes. As they get started, students may struggle with decomposing shapes into equal shares.
Key Concepts:
 Circles and rectangles can be partitioned into two smaller equal shares (use the terminology halves and half of) and describe the whole as two of the smaller equal shares.
 Circles and rectangles can be partitioned into four smaller equal shares (use the terminology fourths, quarters, fourth of, and quarter of) and describe the whole as four of the smaller equal shares.
Prior Knowledge Needed:
 Describe and compare measurable attributes; (Grade K, Unit 8; K.MD.A.1, K.MD.A.2)
 Modeling and composing shapes; (Grade K, Unit 15; K.G.B.5)
 Defining attributes of circles and squares; (Grade K, Unit 11; K.G.B.4)
Units on the Horizon:
 Partition circles and rectangles into 2, 3, and 4 parts; identify parts as halves, thirds, and quarters, recognize that equal shares of identical wholes need not have the same shape (Grade 2, Unit 10; 2.G.A.3)
 Partition shapes into parts with equal areas, express the area of each as a unit fraction of the whole (Grade 3, Unit 4; 3.G.A.2)
Lessons

Lesson objective: Understand that shapes can be partitioned into two equal shares that we call halves, and that those two shares together equal one whole. Students bring prior knowledge of modeling and composing shapes from Grade K, Unit 15, K.G.B.5. Th...

Lesson objective: Partition shapes into halves. This lesson helps to build fluency with partitioning shapes into halves. Basic shapes are used here because they help support student understanding of fractional models in the future. This work develops st...

Lesson objective: Understand that shapes can be partitioned into four equal shares that we call fourths, and that those four shares together equal one whole. Students bring prior knowledge of modeling and composing shapes from Grade K, Unit 15, K.G.B.5....

Lesson objective: Partition shapes into fourths. This lesson helps to build fluency with partitioning shapes into fourths. Basic shapes are used here because they help support student understanding of fractional models in the future. This work develops ...

Lesson objective: Apply knowledge of partitioning shapes into halves and fourths to solve a realworld problem. This lesson provides an opportunity for students to apply their knowledge and understanding of partitioning shapes into halves and fourths to...