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5th Grade Fractions Unit

Learning Module

Overview

Learning Module Objectives:

5.NF.A Use equivalent fractions as a strategy to add and subtract fractions.

5.NF.B Apply and extend previous understandings of multiplication and division.

These objectives are standards from the Common Core State Standards for fifth grade.

Prerequisite skills:

  • Building fractions from unit fractions by applying and extending previous understandings of operations on whole numbers
  • Perform operations such as adding, subtracting, multiplying, and dividing of whole numbers

Essential Vocabulary for this unit:

  • Common denominator, common multiple, equivalent fractions, mixed number, simplest form
  • Numerator, product, dividend, equation, quotient

Looking ahead:

  • In sixth grade, students will apply and extend previous understandings of multiplication and division to divide fractions by fractions under the number system domain.

Common Denominators and Equivalent Fractions

 

For the Student

You can use a common denominator or a common multiple of two or more denominators to write fractions that name the same part of a whole.

A common denominator is a common multiple of two or more denominators.

Strategy 1

  • Multiply the denominators to find a common denominator
  • A common denominator of ⅓ and ¼ is 12 because 3x4 = 12
  • Write ⅓ and ¼ as equivalent fractions using the common denominator
  • 1/3 = 4/12
  • 1/4 = 3/12

Strategy 2

  • Make a list of nonzero multiples of 3 and 4
  • Multiples of 3: 3,6,9,12,15,18,21
  • Multiples of 4: 4,8,12,16,20,24
  • Circle the common multiples
  • Use the common multiples as a common denominator to write equivalent fractions of ⅓ and ¼

Next, watch the following lesson for more examples:

Media embedded July 13, 2018

Read through this lesson as well.

 

Homework:

  1. Comment - Which strategy do you prefer to find common denominators and why?
  2. Update - Post a video of yourself teaching how to find a common denominator of two different fractions and then find the equivalent fractions.
  3. Reply (2 peers) - Provide feedback for two of your peers regarding the accuracy of their math work.

For the Teacher

Purpose of this update: This module is the foundation for the upcoming modules. With this lesson, students learn what common denominators are and how to use them to find equivalent fractions. This is crucial for them to grasp before learning how to add and subtract fractions with unlike denominators.

Teaching tips: When creating equivalent fractions, students may not recall to change both the numerator and denominator. Thus, it is key to reiterate this particular step.

Extension: Some students may grasp this quicker than others. One way to involve them in a critical thinking activity is to ask them to make a Venn Diagram (similar to the one below) to find the least common multiples of three given numbers.

 

Addition with Unlike Denominators

For the Student

Objective: Use equivalent fractions as a strategy to add and subtract fractions

To add fractions with unlike denominators you must find a common denominator of both fractions first.

As you watch the lesson below pause it periodically to determine the common denominator of the given problem on your own.

Media embedded July 13, 2018

Next, answer the following practice problems

 

Homework:

  1. Comment - In what aspects of life will one ever come across needing to add fractions?
  2. Update -Find two fractions with different denominators from any recipe. Add the two fractions together by showing all of your work. Take a picture or video of the solution and post it.
  3. Reply (2 peers) - Solve their problems on your own and post a picture of the solution. If you disagree with their work please explain why.

For the Teacher

Purpose of this update: In this module, students are asked to solve addition of fractions with unlike denominators. Previously, students have learned the concept of fractions as well as how to find common denominators. Much of this lesson is a review. Next, students will use the foundation from this module to subtract fractions with unlike denominators.

 Teaching tips: A common misconception is that students will add the numerator and the denominator across without finding a common denominator. During the whole group lesson, reiterate the important of adding things that are like. The concept of sameness: one cannot add apples and bananas.

ELL suggestions: Provide sentence frames for students to use when responding to questions and make a vocabulary chart to help English Language Learners choose the right words.

 

Subtraction with Unlike Denominators

For the Student

When subtracting two fractions with unlike denominators, follow the same steps you follow when adding two fractions. However, instead of adding the fractions, you now subtract.

As you watch the following lesson try to think of the common denominators on your own. 

Media embedded July 13, 2018
 
 

Next, solve the following practice problems and remember to simplify your answers. 

 

Homework:

  1. Comment - Benchmarks are numbers used to estimate the sum or difference of fractions. The benchmarks are: 0, ½ and 1. Solve the following problem and explain how you know your answer is reasonable: 9/10 - ⅖.
  2. Update - Create a word problem that involves finding the difference of two fractions. Solve your problem and post the solution.
  3. Reply (2 peers) - Reply by taking a video of yourself discussing why you think your peer is correct or incorrect in solving their own word problem. If they are incorrect, discuss the correct solution.

For the Teacher

Purpose of this update: Previously, students learned and practice how to add fractions with unlike denominators. Similarly, they will be following the same steps as above to find the difference of two fractions.

Teaching tips: Many students might have a difficult time with finding common denominators to add and subtract fractions. The ease their understanding, present them with fraction strips such as these: 

Other resources: In the following video, a few examples are shown on how to use fraction strips to find the difference of two fractions.

Media embedded July 13, 2018

 

Add and Subtract Mixed Numbers

For the Student

A mixed number is a number consisting of an integer and a proper fraction.

Strategy 1

  • Turn the mixed numbers to improper fractions by multiplying the integer with the denominator and adding numerator
  • Example: 2 ⅕ = 11/5
  • Then, find a common denominator for the two fractions and make equivalent fractions
  • Lastly, add or subtract the two new fractions and simplify your answer

Strategy 2

  • Add the two integers (whole numbers) together first
  • Then, find a common denominator for the two proper fractions and make equivalent fractions
  • Add or subtract the two fractions and combine it with the integers
Media embedded July 13, 2018
Media embedded July 13, 2018

Complete the following example problems

 

Homework:

  1. Comment - Solve the following problem and write your answer in a complete sentence. Julie has 5 and ¼ cups of sugar. Lily has 4 and ⅓ cups of sugar. How many cups of sugar do Julie an Lily have altogether?
  2. Update -Create two word problems and include their solutions in your update. One word problem should include adding mixed numbers and the other, subtracting.
  3. Reply (2 peers) -Provide feedback to two of your peers on their creativity and accuracy of the two word problems and their solutions.

For the Teacher

Purpose of this update: In this module, students are asked to further their knowledge of fractions by turning mixed numbers into improper fractions to add and subtract them in various ways.

Teaching tips: In this concept, there are multiple steps involved and students may forget to complete a few steps along the way. Provide an anchor chart with steps for students to follow as the one below to help them through the process.

 

Subtraction with Renaming (Regrouping)

For the Student

An improper fraction is a fraction greater than one. The numerator is bigger than the denominator.

Strategy 1

  • Find a common denominator for the two given mixed numbers
  • Use the common denominator to write equivalent fractions with like denominators
  • Rename the first mixed number with a fraction greater than 1
  • Then, find the difference of the fractions first then of the whole numbers
  • Lastly, simplify your answer

Strategy 2

  • Write equivalent fractions using a common denominator for the two given mixed numbers
  • Rename both mixed numbers as fractions greater than 1
  • Find the difference and make sure to simplify your answer

Here, is an example problem and its solution. Watch it carefully and take notes.

Media embedded July 13, 2018

Next, read through this lesson

 

Homework:

  1. Comment - Explain the ways in which the two strategies differ. Explain which strategy you prefer and why.
  2. Update - (1) When you subtract mixed numbers, how do you decide when a mixed number needs to be renamed? (2) Solve the following problems in simplest form and use both strategies at least once. Take a picture of your solution processes for peer review.
  3. Reply (2 peers) - Explain why you agree or disagree with your peer for part one. For part two, check to see if your answers match your peers’ answer. If so, provide them with a follow up challenge question. If not, explain where they have made errors and the corrections that should be made.

For the Teacher

Purpose of this update: In this update, students are asked to rename mixed numbers to find their differences. This concept provides students a way to hone their skills with making improper fractions, renaming, subtraction, as well as simplifying.

Teaching tips: This is a concept that needs much practice due to the many steps involved. Many students will unnecessarily rename fractions, thus, it is crucial to discuss when one should rename and one does not need to. As the previous concept, it would be beneficial for the students to have a visual of all the steps involved in solving these problems. Also, during this module it would be a great opportunity to review the previously learned concepts and vocabulary words.

Other resources:

 

Multiply Fractions

For the Student

Objective: Apply and extend previous understandings of multiplication and division

A product is the answer to a multiplication problem.

When multiplying fractions, first multiply the numerators across then multiply the denominators across. If one of the factors is a whole number, then rewrite the number as a fraction with a denominator of one. Lastly, reduce the fraction in its simplest form.

  • Example: 3/5 x 2/6 = 3x2/5x6 = 6/30 = 1/5 

Read through this lesson to view examples. 

Next, play this game to practice on your own!

 

Homework:

  1. Comment - What is the difference between a numerator and a denominator?
  2. Update - Post a video of yourself solving five examples of multiplying fractions. The answers should be in simplest form.
  3. Reply (2 peers) - Give your peers feedback in the following areas: accuracy and clarity.

For the Teacher

Purpose of this update: Multiplying fractions is one of the easier concepts for students to grasp. In this module, students are practice multiplying numerators and denominators across and simplifying their answers.

Teaching tips: When multiplying a fraction by a whole number or a whole number by a fraction, it is not necessary for students to change the whole number into a fraction. Some students will be able to simply multiply the whole number with the numerator and keep the denominator the same. Let students choose their method of choice.

Misconception: On the contrary, students may multiply the whole number fraction and the denominator instead of the numerator or both.

ELL strategies: Visuals are great way to expose English Language Learners to math topics. Fraction circles or equal groups demonstrate understanding of fraction operations.

Here, is an example of a visual representation of multiplying fractions: 

Media embedded July 13, 2018

Other resources: 

 

 

Multiply Mixed Numbers

For the Student

Earlier, you were introduced to mixed numbers and how to add and subtract them. In this lesson, you will learn how to multiply mixed numbers.

Recall: a mixed number is composed of an integer and a proper fraction.

Go through this lesson to learn how to multiply mixed numbers. 

Watch this video to see Sal work through an example:

Media embedded July 13, 2018

Then, complete the following practice problems on your own. If you get stuck, make sure to use the hints to help you solve the problem: Khan Academy - Practice Problems 

 

Homework:

  1. Comment - When would you ever have to multiply fractions in real life? Provide two different examples.
  2. Update - Post a lesson of yourself teaching how to multiply mixed numbers by solving the problems below. Then, create a word problem on your own and solve it as well. (1) Matthew and Rudy each made a bowl of punch. Rudy used 4 1/2 times as much lemonade as Matthew did. If Matthew used 1 1/5 cups of lemonade, how many cups of lemonade did Rudy use? Simplify your answer and write it as a proper fraction or as a whole or mixed number. (2) Linda used 4 2/3 tomatoes to make salad. Luke used 1 2/7 times as much of tomatoes as Linda did. How many tomatoes did Luke use? Simplify your answer and write it as a proper fraction or as a whole or mixed number.
  3. Reply (2 peers) - Give your peers feedback in the following areas: accuracy and clarity.

For the Teacher

Purpose for this update: In this update, students are again presented with mixed numbers. Now, they will be asked to multiply them by fractions, whole numbers, and other mixed numbers. This skill can be applied to everyday life.

Teaching tips: A potential math talk could include ways in which multiplying mixed numbers are used in everyday life. Such as increasing or decreasing a recipe or finding the total amount of money earned after working a fraction of an hour. Encourage students to think of other scenarios.

Misconceptions: Students may multiply the whole numbers and then multiply the fractions instead of turning them into improper fractions. An anchor chart showing the steps will help students remember the steps such as the one below:

 

Divide Fractions

For the Student

A dividend is the number that is to be divided in a division problem.

A quotient is the answer to a division problem, not including the remainder.

This lesson shows the steps to dividing fractions. 

Next, carefully watch this video to view more examples: 

Media embedded July 13, 2018

Now, your turn to practice! Play this game to answer some problems on your own! 

 

Homework:

  1. Comment - Think of a real world situation in which you would need to divide fractions.
  2. Update - Find an object that can be divided, preferably by cutting. Measure the item in inches or feet and decide what fraction you would like to divide it by. Post a video of yourself dividing the object and verbally provide the equation as well as the solution.
  3. Reply (2 peers) -Provide feedback to your peers regarding creativity and accuracy of their work.

For the Teacher

Purpose of this update: In this update, students extend their knowledge of multiplication an division of whole numbers to now divide fractions.

Teaching tips: To divide fractions, you must multiply the first fraction by the reciprocal of the other. Another way would be to cross multiply to find the answer. Students may choose any method that they feel comfortable with. A good way to teach students the steps are the phrases: keep, change, flip. You keep the first fraction, you change the sign from division to multiplication, and you flip (find the reciprocal) of the second fraction. This strategy is quite helpful to most.

Other resources: This anchor chart lays out the various steps in a organized form. Creating a handout similar to this anchor chart would be a great resource for students to revisit as they try problems on their own.

 

Peer Reviewed Work

For the Student

For the peer review project, you will be creating a video lesson in which you will solve your own created problems. For the video lesson you will choose five from the following eight topics and a questions pertaining to each topic. These problems should be different than previous ones you have posted on your updates.

Each problem that you present should be followed by a paragraph explaining the problem and solution. Make sure to include vocabulary words and thoroughly explain your thought process.
 

Topis:

  • Common Denominators and Equivalent Fractions
  • Addition with unlike denominators
  • Subtraction with unlike denominators
  • Add and Subtract Mixed Numbers
  • Subtraction with Renaming (Regrouping)
  • Multiply Fractions
  • Multiply Mixed Numbers
  • Divide Fractions

Rubric:

 

 

For the Teacher

This peer-reviewed project is the final assessment for this learning module. Allowing students to demonstrate their understanding of the concepts using a creative platform strays away from the traditional paper tests. It also allows them to delve into their ingenuity based on their interest. Students will also be able to access their creative work in the future and it will act as an example for future students. Ideally, this work should be assigned by the fourth update so that students have sufficient time to complete the task.

Here is the rubric to assess the work:  

 

Knowledge Survey

For the Student

For the Teacher

This knowledge survey is a formative assessment to provide the teacher with data needed to extend or reteach a lesson. This survey can be used as a pre-test, midpoint check, and an end of the lesson test.