Curriculum / Math / 5th Grade / Unit 5: Multiplication and Division of Fractions / Lesson 21
Math
Unit 5
5th Grade
Lesson 21 of 25
Jump To
Solve real-world problems involving division with fractions and create real-world contexts for expressions involving division with fractions.
The core standards covered in this lesson
5.NF.B.7.C — Solve real world problems involving division of unit fractions by non-zero whole numbers and division of whole numbers by unit fractions, e.g., by using visual fraction models and equations to represent the problem. For example, how much chocolate will each person get if 3 people share 1/2 lb of chocolate equally? How many 1/3-cup servings are in 2 cups of raisins?
5.OA.A.2 — Write simple expressions that record calculations with numbers, and interpret numerical expressions without evaluating them. For example, express the calculation "add 8 and 7, then multiply by 2" as 2 × (8 + 7). Recognize that 3 × (18932 + 921) is three times as large as 18932 + 921, without having to calculate the indicated sum or product.
The foundational standards covered in this lesson
3.OA.A.1 — Interpret products of whole numbers, e.g., interpret 5 × 7 as the total number of objects in 5 groups of 7 objects each. For example, describe a context in which a total number of objects can be expressed as 5 × 7.
3.OA.A.2 — Interpret whole-number quotients of whole numbers, e.g., interpret 56 ÷ 8 as the number of objects in each share when 56 objects are partitioned equally into 8 shares, or as a number of shares when 56 objects are partitioned into equal shares of 8 objects each. For example, describe a context in which a number of shares or a number of groups can be expressed as 56 ÷ 8.
3.OA.B.6 — Understand division as an unknown-factor problem. For example, find 32 ÷ 8 by finding the number that makes 32 when multiplied by 8.
The essential concepts students need to demonstrate or understand to achieve the lesson objective
Suggestions for teachers to help them teach this lesson
There are two interpretations for division: (a) equal group with group size unknown division (also called partitive or sharing division), and (b) equal group with number of groups unknown division (also called quotitive or measurement division). In Grade 5, students apply and extend this understanding of the two types of division with whole numbers to divide unit fractions by whole numbers and whole numbers by unit fractions. To develop an understanding of the division of a unit fraction by a whole number, they use unknown group size division, such as in the problem “$$\frac12$$ meter of cloth is cut into three equal pieces. How long is each piece of fabric?”. Inversely, to develop an understanding of the division of a unit fraction by a whole number, they use unknown number of groups division, such as in the problem, “Three meters of cloth are cut into $$\frac12$$ meter strips. How many strips are cut?” That way, as Bill McCallum notes, “students can build on their understanding of whole-number division without having to grapple with fractional groups, so long as they understand both of these interpretations of division” (“Fraction division part 2: Two interpretations of division”, Mathematical Musings). Thus, students are exclusively given group size unknown division problems in Lesson 19 and number of groups unknown division problems in Lesson 20 to help them build a strong conceptual understanding of fraction division before seeing other types of division problems in Lesson 21.
Students’ work with fraction division only spans three lessons, Lessons 19–21. You may choose to give students much more time with each of these concepts, perhaps spanning each lesson over two days. If you decide to do so, here are some recommendations for where to source additional practice problems that align to this lesson:
Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.
Tasks designed to teach criteria for success of the lesson, and guidance to help draw out student understanding
Jenny buys 2 feet of string. If this is one-third the amount she needs to make a bracelet, how many feet will she need?
a. Draw a diagram to represent the problem.
b. Write an expression to represent the problem.
c. Find how many feet of string Jenny needs.
Grade 5 Mathematics > Module 4 > Topic G > Lesson 25 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..
a. Match each division expression (cut out from Template: Fraction Division Sort) with a situation (cut out from Template: Fraction Division Sort). Some expressions do not have a matching situation.
b. Answer each question. Be prepared to share your reasoning.
Grade 5 Unit 3 Lesson 15 is made available by Open Up Resources under the CC BY 4.0 license. Copyright © 2017 Open Up Resources. Download for free at openupresources.org. Accessed Nov. 19, 2019, 9:44 a.m..
a. Write a story context that can be solved using the expression $${2\div{1\over4}}$$.
b. Write a story context that can be solved using the expression $${{1\over3}\div4}$$.
Problem Set
Unlock the answer keys for this lesson's problem set and extra practice problems to save time and support student learning.
A task that represents the peak thinking of the lesson - mastery will indicate whether or not objective was achieved
Anej has $$1\over2$$ of his birthday cake leftover. He wants to share it equally with his 3 friends. What fraction of the original cake should Anej and his 3 friends get?
Norma has 8 red colored pencils. This is $$1\over3$$ of the total colored pencils she has. How many colored pencils does Norma have altogether?
An example response to the Target Task at the level of detail expected of the students.
The Extra Practice Problems can be used as additional practice for homework, during an intervention block, etc. Daily Word Problems and Fluency Activities are aligned to the content of the unit but not necessarily to the lesson objective, therefore feel free to use them anytime during your school day.
Extra Practice Problems
Answer keys for Problem Sets and Extra Practice Problems are available with a Fishtank Plus subscription.
Help students strengthen their application and fluency skills with daily word problem practice and content-aligned fluency activities.
Lesson 20
Lesson 22
Topic A: Fractions as Division
Relate equal shares of objects to division expressions and visual representations of fractions.
5.NF.B.3
Write division expressions that represent fractions and vice versa.
Solve division problems when the quotient is a fraction or mixed number, including cases with larger values.
Create a free account to access thousands of lesson plans.
Already have an account? Sign In
Topic B: Multiplying a Fraction by a Whole Number
Multiply a fraction by a whole number where the product is a whole number.
5.NF.B.4.A 5.NF.B.6
Multiply a fraction by a whole number where the product is a whole number or a fraction.
Relate multiplication of a fraction by a whole number to multiplication of a whole number by a fraction and use this to develop a general method to multiply any fraction by any whole number (or vice versa).
5.NF.B.4.A 5.NF.B.5
Solve real-world problems involving multiplication of fractions and whole numbers and create real-world contexts for expressions involving multiplication of fractions and whole numbers.
5.NF.B.4 5.NF.B.6 5.OA.A.2
Topic C: Multiplying a Fraction by a Fraction
Multiply a fraction by a fraction without subdivisions using tape diagrams and number lines.
5.NF.B.4 5.NF.B.5 5.NF.B.6
Multiply a fraction by a fraction with subdivisions using tape diagrams and number lines.
Multiply a fraction by a fraction with more complicated subdivisions using an area model.
Develop a general method to multiply a fraction by a fraction.
Solve real-world problems involving multiplication of fractions with fractions and create real-world contexts for expressions involving multiplication of fractions with fractions.
Topic D: Multiplying with Mixed Numbers
Multiply mixed numbers by whole numbers.
Multiply mixed numbers by fractions.
Multiply mixed numbers by mixed numbers.
Develop a general method to multiply with mixed numbers.
Solve real-world problems involving multiplication with mixed numbers and create real-world contexts for expressions involving multiplication with mixed numbers.
Interpret multiplication as scaling.
5.NF.B.5 5.NF.B.5.A 5.NF.B.5.B
Topic E: Dividing with Fractions
Divide a unit fraction by a whole number.
5.NF.B.7.A 5.NF.B.7.C
Divide a whole number by a unit fraction.
5.NF.B.7.B 5.NF.B.7.C
5.NF.B.7.C 5.OA.A.2
Topic F: Fraction Expressions and Real-World Problems
Solve real-world problems involving multiplication and division with fractions.
5.NF.B.3 5.NF.B.6 5.NF.B.7
Write and evaluate numerical expressions involving operations with fractions.
5.NF.B.3 5.NF.B.4 5.NF.B.5 5.NF.B.6 5.NF.B.7 5.OA.A.1 5.OA.A.2
Topic G: Line Plots
Create line plots.
5.MD.B.2
Solve problems involving information presented in a line plot (dot plot).
See all of the features of Fishtank in action and begin the conversation about adoption.
Learn more about Fishtank Learning School Adoption.
Yes
No
Access rigorous, relevant, and adaptable math lesson plans for free