Grade 5Math

Divide a Whole Number by a Unit Fraction

Divide a Whole Number by a Unit Fraction is a skill on Pengi from Lesson 11: Reason About Quotients in Illustrative Mathematics, Grade 5.

Key Concepts

Property To divide a whole number by a unit fraction, you can multiply the whole number by the denominator of the fraction. This is because you are finding how many fractional parts fit into the whole number. $$a \div \frac{1}{b} = a \times b$$.

Examples How many $\frac{1}{4}$ cup servings are in 3 cups of sugar? $$3 \div \frac{1}{4} = 3 \times 4 = 12$$ A ribbon is 5 meters long. How many $\frac{1}{3}$ meter pieces can be cut from it? $$5 \div \frac{1}{3} = 5 \times 3 = 15$$.

Explanation Dividing a whole number by a unit fraction asks the question, "How many of these fractional pieces fit into the whole amount?" For example, $2 \div \frac{1}{4}$ is asking how many quarter pieces fit into 2 wholes. Since there are 4 quarters in 1 whole, there must be $2 \times 4 = 8$ quarters in 2 wholes. This concept is the inverse of dividing a fraction by a whole number.

Common Questions

What is Divide a Whole Number by a Unit Fraction?

Divide a Whole Number by a Unit Fraction is a skill on Pengi from Lesson 11: Reason About Quotients in Illustrative Mathematics, Grade 5.

What grade level is Divide a Whole Number by a Unit Fraction for?

Divide a Whole Number by a Unit Fraction is part of the Grade 5 Math curriculum, covered in Illustrative Mathematics, Grade 5. It is designed for students studying Math at the Grade 5 level.

How can I learn Divide a Whole Number by a Unit Fraction?

Pengi offers an AI-guided lesson for Divide a Whole Number by a Unit Fraction that walks you through the key concepts step by step. The lesson is aligned to Illustrative Mathematics, Grade 5 so the content matches what you see in class.

How do I practice Divide a Whole Number by a Unit Fraction?

After learning the concept, use the Practice mode to work through targeted exercises on Divide a Whole Number by a Unit Fraction. The AI adapts to your level and gives feedback on each answer so you can identify and fix mistakes.

Which textbook covers Divide a Whole Number by a Unit Fraction?

Divide a Whole Number by a Unit Fraction is covered in Illustrative Mathematics, Grade 5, specifically in Chapter 3: Multiplying and Dividing Fractions under Lesson 11: Reason About Quotients. Pengi's lesson is aligned directly to this textbook so you can follow along with your class.

Is Divide a Whole Number by a Unit Fraction free to study on Pengi?

Yes, the core Learn and Practice modes for Divide a Whole Number by a Unit Fraction are available for free on Pengi. No credit card is required to start studying.