Prior to this unit, in Grades 1 and 2, students work with partitioning shapes. They have some familiarity with vocabulary related to partitioning shapes from those grades, espically "halves", "thirds", and "fourths", but have yet to name those parts using numbers. This unit marks the first time third graders are officially introduced to fractions as numbers (and their numerical representations).

In this unit, students will come to understand unit fractions and use them to build other fractions. This idea is tightly connected to what students know about using "1" to build other whole numbers. Students are likely to struggle with understanding that fractions are one number, rather than two. They will use number lines to explore how fractions are numbers that live on the number line with the whole numbers they already know.

**Key Concepts:**

- Fractions are numbers that describe a quantity that results from partitioning a whole.
- Just as whole numbers denote a collection of whole units, fractions denote a collection of unit fractions.
- When a whole is partitioned into \(b\) equal sized pieces, each piece is \(\frac1b\) of the whole. It takes \(b\) of these pieces to make the whole. When we take \(a\) of those pieces, the result is \(\frac ab\).
- Fractions live on the number line denoting a distance from 0, just as whole numbers do.

**Prior Knowledge Needed:**

- Partition shapes into fair shares; (Grade 1, Unit 17; 1.G.A.3)
- Partition shapes into fair shares; (Grade 2, Unit 10; 2.G.A.3)

**Units on the Horizon:**

- Using Fractions in Measurement and Data; (Grade 3, Unit 5)
- Understanding Equivalent Fractions; (Grade 3, Unit 10)
- Comparing Fractions; (Grade 3, Unit 11)
- Understanding Fraction Equivalence and Comparison; (Grade 4, Unit 5)

## Lessons in this unit have been temporarily archived as they undergo maintenance work.

## Lessons