Naming Common Fractional Units
Naming Common Fractional Units teaches Grade 3 students to identify what to call the equal parts created when a whole is divided. From Eureka Math Grade 3: dividing a whole into 2 equal parts gives halves (1/2 each), 3 parts gives thirds (1/3 each), 4 parts gives fourths (1/4 each), 6 parts gives sixths (1/6 each), and 8 parts gives eighths (1/8 each). The name of the fractional unit always matches the denominator. This naming skill connects the visual act of partitioning to the standard fraction vocabulary used in all future fraction work.
Key Concepts
Property When a whole is divided into a specific number of equal parts, we name the fractional unit based on that number. 2 equal parts $\rightarrow$ halves ($\frac{1}{2}$) 3 equal parts $\rightarrow$ thirds ($\frac{1}{3}$) 4 equal parts $\rightarrow$ fourths ($\frac{1}{4}$) 6 equal parts $\rightarrow$ sixths ($\frac{1}{6}$).
Examples A pizza cut into 2 equal slices is divided into halves. Each slice is one half ($\frac{1}{2}$) of the whole pizza. A chocolate bar broken into 4 equal pieces is divided into fourths. Each piece is one fourth ($\frac{1}{4}$) of the whole bar. A ribbon cut into 6 equal parts is divided into sixths. Each part is one sixth ($\frac{1}{6}$) of the whole ribbon.
Explanation This skill introduces the specific names for common fractions you will encounter. The name of the fraction, like "third" or "fourth," tells you how many equal parts the whole has been divided into. For example, the word "fourth" signals that the whole is split into 4 equal pieces, and each piece is a unit fraction of $\frac{1}{4}$. Knowing these names helps you quickly understand and describe parts of a whole.
Common Questions
What do you call equal parts when a whole is divided into 2?
Halves. Each part is 1/2.
What do you call equal parts when a whole is divided into 4?
Fourths (or quarters). Each part is 1/4.
What do you call equal parts when a whole is divided into 6?
Sixths. Each part is 1/6.
How does the fractional unit name relate to the denominator?
The denominator tells you how many equal parts the whole was divided into, and the fractional unit name comes from that number.
What are the most common fractional units in Grade 3?
Halves (2), thirds (3), fourths (4), sixths (6), and eighths (8).
Why is naming fractional units important?
The name identifies what each piece represents and is the foundation for reading, writing, and comparing fractions correctly.