Develop Skills and Strategies Lesson 17 Part 1: Introduction CCSS 3.NF.A.3b 3.NF.A.3c Find Equivalent Fractions In Lesson 16, you learned that equivalent fractions tell about the same amount of the whole. Take a look at this problem. Izzy’s mom baked a cake. She put chocolate frosting on half of the cake and vanilla frosting on half of the cake. Then Izzy’s mom cut the cake into fourths. What is a different fraction that names the part of the cake that has chocolate frosting? Explore It Use the math you already know to solve the problem. Look at the picture above. What fraction of the cake has chocolate frosting? How many equal parts should the cake be divided into to show fourths? On the picture above, draw lines to divide the cake into fourths. How many fourths of the cake have chocolate frosting? Did the amount of cake with chocolate frosting change? Explain how you know that 1 of the cake is the same as 2 . 2 ·· 4 ·· 150 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 1: Introduction Lesson 17 Find Out More In the last lesson, you looked at stacked models to understand equivalent fractions. Both models were the same size, but divided into a different number of equal parts. You looked for fractions that named the same amount of the whole. You can also find equivalent fractions by dividing the same model in different ways. The cake already showed 1 . You may have drawn lines in one of these ways to 2 ·· show fourths. No matter how the fourths are made, the models show that 2 of the cake has 4 ·· chocolate frosting. You can also divide a number line in different ways to show that 1 is equivalent to 2 . 2 ·· 1 2 0 0 1 4 2 4 4 ·· 1 3 4 1 Reflect 1 Izzy’s mom now wants to cut the cake into eighths. Explain how to figure out how many eighths of the cake have chocolate frosting. L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 151 Part 2: Modeled Instruction Lesson 17 Read the problem below. Then explore different ways to think about equivalent fractions. Casen ate 2 of an orange. Trey’s orange is the same size. He ate 1 of it. Show 8 ·· 4 ·· that the two boys ate the same amount. Picture It You can use models to help find equivalent fractions. This model shows 2 . This model shows 1 . 8 ·· 4 ·· Look at the model of 2 . The solid lines show the division into fourths. The dotted 8 ·· lines show how each fourth was divided to make eighths. Model It You can also use a number line to help find equivalent fractions. This number line shows both fourths and eighths. 1 4 0 2 4 3 4 1 0 1 2 3 4 5 6 7 1 152 8 8 8 8 8 8 8 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 2: Guided Instruction Lesson 17 Connect It Now you will solve the problem from the previous page using equations. 2 How do you know that 2 of the first model are shaded? 8 ·· 3 How do you know that 1 of the second model is shaded? 4 ·· 4 Explain how the models show that the fractions are equivalent. 5 How does the number line show that the fractions are equivalent? 6 Write sentences to show the fractions of the two oranges name the same amount. use words: Two eighths is equal to . use fractions: equals . 7 Explain how you can show two fractions are equivalent. Try It Use what you just learned to solve these problems. 8 Draw a model to show 2 5 4 . 3 ·· 6 ·· 9 Use the number line to find a fraction equivalent to 1 . 3 ·· 0 1 3 2 3 1 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 153 Part 3: Modeled Instruction Lesson 17 Read the problem below. Then explore different ways to write a whole number as a fraction. Kacey used 2 same-sized boards to build a birdhouse. He cut each board into fourths. How can you write 2 as a fraction to show Kacey’s boards divided into fourths? Picture It You can use models to help you write a whole number as a fraction. The fraction strips below show 2 wholes, each divided into fourths. 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 Each part is 1 of a whole. There are eight 1 s in all. 4 ·· 4 ·· Model It You can use a number line to help you write a whole number as a fraction. This number line shows whole numbers on the top and fourths on the bottom. 0 0 1 1 4 2 4 3 4 4 4 2 5 4 6 4 7 4 8 4 Notice that each whole number has an equivalent fraction. 154 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 3: Guided Instruction Lesson 17 Connect It Now you will solve the problem from the previous page using equations. 10 Look at the models on the previous page. How many equal parts are in 1 whole? Explain how you know. 11 How many parts are in 2 wholes? Explain how you know. 12 Write sentences to show the fraction that is equivalent to 2. use words: Two wholes equals . use a fraction: 2 equals . 13 Explain how to find a fraction equivalent to a whole number. Try It Use what you just learned to solve these problems. 14 Use the model to find a fraction equivalent to 3. 15 Draw a model to show 3 5 18 . 6 ·· 3 5 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 155 Part 4: Modeled Instruction Lesson 17 Read the problem. Then explore different ways to write a whole number as a fraction with a denominator of 1. Justin picked 4 green peppers from his garden. He did not cut them into pieces. How can you write 4 as a fraction to show Justin’s green peppers? Picture It You can use models to help you write a whole number as a fraction with a denominator of 1. Each circle stands for 1 green pepper. They are not divided into pieces, so each whole is made of one part. Model It You can use a number line to help you write a whole number as a fraction with a denominator of 1. This number line shows whole numbers on the top and fractions on the bottom. 0 1 2 3 4 0 1 1 2 1 3 1 4 1 Notice that each whole number has an equivalent fraction. The spaces between whole numbers are not divided into parts. Each whole number is made of one part, so the denominator is 1. 156 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 4: Guided Instruction Lesson 17 Connect It Now you will solve the problem from the previous page. 16 Explain how you know each whole only has 1 part. 17 How many parts do the 4 green peppers make? 18 What does the numerator of a fraction show? 19 What does the denominator of a fraction show? 20 Write a fraction equivalent to 4. number of parts 1 Remember: ·························· number of equal parts in a whole 2 21 Explain how to write a whole number as a fraction with a denominator of 1. Why does this work? Try It Use what you just learned to solve these problems. 22 Use the model to find a fraction equivalent to 6. 6 5 23 Draw a model to show 5 5 5 . 1 ·· L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 157 Part 5: Guided Practice Lesson 17 Study the model below. Then solve problem 24–26. Student Model The student used solid lines to show fourths and dotted lines to show eighths. Caleb and Hannah bought two melons that are the same size. Caleb cut his into fourths. Hannah cut hers into eighths. Hannah ate 4 of her melon, and Caleb ate an equal amount of 8 ·· his melon. What fraction did Caleb eat? Look at how you could show your work using a model. Pair/Share How could you solve this problem using a number line? How many thirds are in 1 whole? How many eighths are in 1 whole? Solution: Caleb ate 2 of his melon. 4 ·· 3 8 24 Matt says is equivalent to 1. Elisa says is equivalent to 1. 3 8 ·· ·· Who is correct? Show your work. Pair/Share What is another fraction that is equivalent to 1? 158 Solution: L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 5: Guided Practice 25 Show two fractions that are equivalent to 5. Show your work. Lesson 17 There will be 5 wholes in all. Think about how many parts will be in each whole. Pair/Share Solution: 26 Kaia ate 3 of a banana. Zoie ate an equivalent amount. Which 6 ·· fraction shows how much Zoie ate? Circle the letter of the correct answer. A 1 How did you decide what denominators to use in your fractions? Look at where 3 is on a 6 ·· number line. What other fraction could be shown at the same point? 3 ·· B 2 3 ·· C 5 8 ·· D 1 2 ·· Landon chose A as the correct answer. How did he get that answer? Pair/Share Does Landon’s answer make sense? L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 159 Part 6: Common Core Practice Lesson 17 Solve the problems. 1 Which fraction shown is equivalent to } 2 ? 6 A B CD 2 Which fraction is equivalent to 3? 3 A } 1 1 B } 3 4 C } 1 6 D } 3 3 Look at point P on the number line. P 0 1 Look at number lines 3a–3c. Is the point on each number line equal to the number shown by point P? Choose Yes or No. a. 0 160 No Yes No Yes No 1 c. 0 Yes 1 b. 0 1 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 6: Common Core Practice Lesson 17 4 For numbers 4a–4d, choose Yes or No to indicate whether each number graphed on the number line represents one whole. a. 0 1 1 2 1 3 1 4 1 0 1 1 2 1 3 1 4 1 0 1 4 2 4 3 4 1 0 1 4 2 4 3 4 4 4 b. c. d. Yes No Yes No Yes No Yes No 5 Use the number line below to find a fraction equivalent to 3. Show your work. 0 1 2 3 Answer 3 is equivalent to 6 Draw a model to find a fraction equivalent to } 1 . 4 Show your work. 1 is equivalent to Answer } 4 Self Check Go back and see what you can check off on the Self Check on page 131. L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 161 Develop Skills and Strategies Lesson 17 Find Equivalent Fractions Lesson Objectives The Learning Progression •Use fraction models and number lines to identify and create equivalent fractions, including those that are greater to or equal to one whole. In previous lessons students learned that more than one fraction can name the same amount or a point on a number line. Students understand that because sixths are smaller than halves, it takes more sixths to cover the same area. In this lesson students extend these ideas to include identifying and generating equivalent fractions for numbers equal to or greater than one whole using fraction models and number lines. •Express whole numbers as fractions. •Identify fractions that are equivalent to whole numbers. Prerequisite SkilLs Students also explore and practice ways to write a •Understand the meaning of fractions. whole number as a fraction with a denominator of 1, •Identify fractions represented by models. such as 3 . Students reason about the size of fractions •Understand that the size of a fractional part is relative to the size of the whole. to solve problems and explain why two fractions are or •Understand how to use number lines to count and identify fractional parts. Vocabulary 1 ·· are not equivalent. Students’ work with equivalent fractions in this lesson provides a foundation for comparing fractions and for solving problems involving fraction operations. There is no new vocabulary. Teacher Toolbox Teacher-Toolbox.com Prerequisite Skills 3.NF.A.3b 3.NF.A.3c ✓✓ ✓ ✓ ✓ Ready Lessons Tools for Instruction Interactive Tutorials CCSS Focus 3.NF.A.3 Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size. b.Recognize and generate simple equivalent fractions, e.g., 1 5 2 , 4 5 2 . Explain why the fractions are equivalent, e.g., by 2 ·· 4 ·· 6 ·· 3 ·· using a visual fraction model. c.Express whole numbers as fractions, and recognize fractions that are equivalent to whole numbers. Examples: Express 3 in the form 3 2 3 ; recognize that 6 5 6; locate 4 and 1 at the same point of a number line diagram. 1 ·· 1 ·· 4 ·· STANDARDS FOR MATHEMATICAL PRACTICE: SMP 1, 2, 4, 6 (see page A9 for full text) 170 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 1: Introduction Lesson 17 At a Glance Develop skills and strategies Students read a word problem and answer a series of questions designed to apply what they know about equivalent fractions. Lesson 17 Part 1: introduction ccss 3.nF.a.3b 3.nF.a.3c Find equivalent Fractions in Lesson 16, you learned that equivalent fractions tell about the same amount of the whole. take a look at this problem. Step By Step Izzy’s mom baked a cake. She put chocolate frosting on half of the cake and •Tell students that this page models how to think about using more than one fraction to name the same amount. vanilla frosting on half of the cake. Then Izzy’s mom cut the cake into fourths. What is a different fraction that •Have students read the problem at the top of the page. names the part of the cake that has chocolate frosting? explore it •Work through Explore It as a class. Draw a model of use the math you already know to solve the problem. the cake on the board and shade 1 to represent the Look at the picture above. What fraction of the cake has chocolate frosting? 2 ·· 1 2 ·· chocolate frosting. Ask a student to show one way to How many equal parts should the cake be divided into to show fourths? 4 On the picture above, draw lines to divide the cake into fourths. divide the cake into fourths on the board. How many fourths of the cake have chocolate frosting? •Ask student pairs or groups to discuss the last 2 4 ·· Did the amount of cake with chocolate frosting change? Explain how you know that 1 of the cake is the same as 2 . 2 4 ·· ·· Possible answer: no, the amount with chocolate frosting did not change. 1 question together and explain how they know. Ask 2 ·· is the same as 2 because the same amount of the cake is shaded. the only 4 ·· them to share why the answer makes sense to them. thing that changed was how many pieces the cake was cut into. Invite volunteers to share. Emphasize that the amount of chocolate frosting did not change and 150 L17: Find Equivalent Fractions ©Curriculum Associates, LLC that 1 and 2 name the same amount of frosting. 2 4 ·· ·· SMP Tip: Students rely on a picture or model of the cake to help conceptualize and gain insight into the problem’s solution and ask themselves if it makes sense (SMP 1). L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Copying is not permitted. Mathematical Discourse •Why does it make sense that 2 and 1 can both name 4 ·· 2 ·· the same amount of frosting? Students should understand that the denominators name different ways to divide the same whole into equal parts and the numerators name parts of the divided whole that are shaded. 171 Part 1: Introduction Lesson 17 At a Glance Students explore using the model for one fraction to make an equivalent fraction by dividing each fractional part into smaller, equal parts. They apply this idea by showing equivalent fractions on a number line. Part 1: introduction Lesson 17 Find out More In the last lesson, you looked at stacked models to understand equivalent fractions. Both models were the same size, but divided into a different number of equal parts. You looked for fractions that named the same amount of the whole. You can also find equivalent fractions by dividing the same model in different ways. Step By Step The cake already showed 12 . You may have drawn lines in one of these ways to ·· show fourths. •Read Find Out More as a class. Explain that previously they showed two fraction models side-byNo matter how the fourths are made, the models show that 2 of the cake has side to see that two fractions were equivalent. Draw a chocolate frosting. model of the cake showing two halves. Direct You can also divide a number line in different ways to show that 1 is equivalent to 2. 4 ·· 2 ·· students’ attention to the three ways to divide the 0 halves into fourths. Ask students to talk with a 0 partner to prove that all the ways to show 2 are equivalent to 1 . Invite students to share. 4 ·· 2 ·· •Emphasize that although each 1 is a different shape, 2 ·· they cover the same amount and they both are the 1 2 1 4 2 4 4 ·· 1 3 4 1 reflect 1 Izzy’s mom now wants to cut the cake into eighths. Explain how to figure out how many eighths of the cake have chocolate frosting. Possible answer: Divide each fourth into 2 equal pieces to make eighths. then count how many eighths are shaded. or divide each section on the number line again and then count how many eighths are the same as 1 . 2 ·· same amount as 1 . 2 ·· •Draw the number line from the page on the board. Point out that they can label the point 1 above the 2 ·· 151 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. line and label fourths below the line to show that 2 and 1 name the same point. 4 ·· 2 ·· •Ask pairs to discuss and answer the Reflect It question. Have them draw the cake on a paper or white board to show one way that 1 is equivalent 2 ·· to 4 . For a quick assessment, have pairs hold up 8 ·· their paper or white board. Call on students to explain how they divided the fourths into eighths. Concept Extension •Up to this point, students have relied on an intuitive notion of congruence or have laid equivalent fractions on top of each other to see Real-World Connection Use two pieces of fruit that are the same size to help students reason that they are getting a fair share or equivalent amount if they cut the same-size fruits into halves two different ways. If two apples are shown standing up, cut one apple in half using a horizontal cut. Cut the other apple using a vertical cut. Emphasize that it’s the same amount, only the shapes are different. Students will need more experiences to develop this understanding over time. 172 that they cover the same amount or area. To help students understand that each 1 is the same 4 ·· amount, cut out 3 models of the cake and shade the ways to show 2 on each. Cut apart the 4 ·· second 2 , rotate it, and place it on top of the 2 on 4 ·· 4 ·· the first model. For the 2 on the 3rd model, cut 4 ·· each 1 apart, and cut it in half, so you can rotate 4 ·· the parts to cover the 2 on the first model. 4 ·· L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 2: Modeled Instruction Lesson 17 At a Glance Part 2: Modeled instruction Students use number lines and fraction models to find equivalent fractions. read the problem below. then explore different ways to think about equivalent fractions. Step By Step •Explain to students that they will now explore more ways to think about equivalent fractions. •Read the problem at the top of the page as a class. Explain that students can use models to prove that the boys ate the same amount as long as the two oranges are the same size. •Read Picture It. Guide students to realize that they can draw rectangle models or use circle models that more closely resembles oranges. Focus students’ attention on the first model that shows 2 . Ask them 8 ·· if they can also see where the fourths are in the model. [The solid lines show fourths.] Ask students to explain how they can get eighths from fourths. [Divide each fourth in half.] Ask students to talk with a partner to explain if it makes sense that both boys ate the same amount and why. Invite students to share their ideas. •Draw a number line from 0 to 1 that shows fourths. Read Model It together and ask students how they could create eighths on the same number line. Invite a student to draw the eighths on the number line on the board. Lesson 17 Casen ate 2 of an orange. Trey’s orange is the same size. He ate 1 of it. Show 8 ·· 4 ·· that the two boys ate the same amount. Picture it you can use models to help find equivalent fractions. This model shows 2 . This model shows 1 . 8 ·· 4 ·· Look at the model of 2 . The solid lines show the division into fourths. The dotted 8 ·· lines show how each fourth was divided to make eighths. Model it you can also use a number line to help find equivalent fractions. This number line shows both fourths and eighths. 1 4 0 2 4 3 4 1 0 1 2 3 4 5 6 7 1 8 152 8 8 8 8 8 8 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. SMP Tip: Draw students’ attention to using this simple circle model can make it easier to see why the same amount of orange can be named by a different fraction 1 2 or 1 2 , depending upon the 8 4 ·· ·· number of pieces in each whole in the model (SMP 4). Concept Extension Mathematical Discourse •Use the number line model on the board to extend •Is it possible to use the fraction circle to find another students’ thinking about other equivalent fractions fraction equivalent to 1 ? How could this be done? 4 ·· A student may say that they could divide each eighths into two equal parts or divide each fourth into 3 equal parts. Ask students to predict the unit fractions that the whole would be divided into. shown on the number line. Ask students to find at least two other fractions that are equivalent 3 3 and 6 4and explain why they are equivalent 4 ·· 8 ·· [same distance from 0 on the number line]. L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 173 Part 2: Guided Instruction Lesson 17 At a Glance Students revisit the problem on page 152 and solve the problem using equations. Lesson 17 connect it now you will solve the problem from the previous page using equations. Step By Step 2 How do you know that 2 of the first model are shaded? 8 ·· there are 8 equal parts and 2 are shaded. •Read and discuss Connect It as a class. For number 6, write the equation 2 5 1 on the board. Ask 8 2 ·· ·· students if there is another way to write the equation. 3 1 5 2 4Focus students’ attention on the 4 8 ·· ·· two numerators. Point out that they divided each 1 part out of 4 into 2 parts. Point to the numerator and explain that when they cut each 1 into two equal 2 ·· parts, they created 8 parts in the whole or eighths. Help students understand that the numbers match what they did when they divided the 1 s into 2 smaller and equal parts. Part 2: guided instruction 4 ·· •For problem 7, ask students to first explain their thinking to a partner. Then invite students to share how they would show that two fractions are equivalent. Look for students to say that the two fractions take up the same space or area on the model or are at the same point on the number line (and same distance from 0). •Ask students to work on the Try It problems in pairs. Draw a rectangle and number line showing thirds on the board. Invite students to come to the board to show how they filled in the models on the page. Be ready to model another way to create sixths from thirds. Draw vertical thirds and draw a horizontal dotted line to cut the rectangle into top and bottom regions, creating sixths. 3 How do you know that 1 of the second model is shaded? 4 ·· there are 4 equal parts and 1 is shaded. 4 Explain how the models show that the fractions are equivalent. the amount that is shaded is the same. 5 How does the number line show that the fractions are equivalent? 1 and 2 are located at the same point on the number line. 8 ·· 4 ·· 6 Write sentences to show the fractions of the two oranges name the same amount. use words: Two eighths is equal to one fourth use fractions: 2 equals 8 ·· 1 4 ·· . . 7 Explain how you can show two fractions are equivalent. you can see if they show the same amount in the model, or you can see if they are at the same point on a number line. try it use what you just learned to solve these problems. 8 Draw a model to show 2 5 4 . 3 ·· 6 ·· Possible drawing: 9 Use the number line to find a fraction equivalent to 1 . 3 ·· 1 3 0 0 1 6 2 6 2 3 3 6 4 6 1 5 6 1 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 153 Try It Solutions 8Solution: Students may draw vertical thirds using a solid line and divide each third into 2 equal parts using dotted vertical lines. Students may choose to divide the model into vertical thirds and then draw one horizontal line through the center of the model to create 6 equal parts. 9Solution: Students use a hash mark to cut each third into 2 equal parts on the number line. They label SMP Tip: Students work with a partner to reason about quantities and their relationships and then create a meaningful representation of two equivalent fractions (SMP 2). Concept Extension •Have students explore other ways that the model could show thirds and then sixths. For example, the students could draw three horizontal lines to show thirds and then draw a vertical line down the center of the rectangle. 174 each 1 . 6 ·· Error Alert: Students who drew in too many lines between each 1 may be confused with drawing 3 ·· two lines in each third, instead of creating 2 equal intervals in each third. Explain that they can draw in 3 equal intervals for each third, but that would create ninths, not sixths. L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 3: Modeled Instruction Lesson 17 At a Glance Part 3: Modeled instruction Students explore different ways to write a whole number as a fraction. Lesson 17 read the problem below. then explore different ways to write a whole number as a fraction. Step By Step Kacey used 2 same-sized boards to build a birdhouse. He cut each board into fourths. How can you write 2 as a fraction to show Kacey’s boards divided into fourths? •Explain to students that they will now look at fractional names for whole numbers. Picture it you can use models to help you write a whole number as a fraction. •Read the problem at the top of the page as a class. Ask students to picture the problem and the 2 samesized boards that are each cut into fourths. The fraction strips below show 2 wholes, each divided into fourths. 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 Each part is 1 of a whole. There are eight 1s in all. •Draw the models from Picture It on the board. 4 ·· 4 ·· Model it Remind students that, previously, they used similar you can use a number line to help you write a whole number as a fraction. models to count by 1 s. Count the fourths together 4 ·· This number line shows whole numbers on the top and fourths on the bottom. 0 aloud and point to each section as students count 0 1 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 2 . 4 ·· 4 ·· 4 ·· 4 ·· 4 ·· 4 ·· 4 ·· 4 ·· •Emphasize that 4 is also 1 whole board and 8 is also 4 4 ·· ·· 1 1 4 2 4 3 4 4 4 2 5 4 6 4 7 4 8 4 Notice that each whole number has an equivalent fraction. 2 whole boards. •Draw the number line as it is shown in Model It on the board. Ask what the numbers show above the line [whole numbers] and what they represent below 154 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. the line [fourths]. Point out that the whole number 1 and the fraction 4 name the same point on the line. 4 ·· Make the same point for 2 and 8 on the number line. 4 ·· •Ask students to use what they know to solve the problem. 3 8 4 4 ·· L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Mathematical Discourse •What is another way you could model the boards problem to show the fraction for two boards? Use fraction tiles or strips or draw pictures of the boards. 175 Part 3: Guided Instruction Lesson 17 At a Glance Students revisit the problem on page 154. They write an equation to show the fraction for two wholes if each whole is divided into fourths. They use models to find fractions that are equivalent to other whole numbers. Part 3: guided instruction Lesson 17 connect it now you will solve the problem from the previous page using equations. 10 Look at the models on the previous page. How many equal parts are in 1 whole? Explain how you know. Possible answer: there are 4 parts in 1 whole. each fraction strip has 4 parts. Step By Step •Work through Connect It problems 10–12 together. 11 How many parts are in 2 wholes? Explain how you know. Possible answer: there are 8 parts in 2 wholes. i counted the number of parts in both •Write the fraction 8 on the board. Ask students to fraction strips. 4 ·· talk to their partners and discuss what each number 12 Write sentences to show the fraction that is equivalent to 2. use words: Two wholes equals means and why the numerator is two times larger than the denominator. •Ask students questions such as: What do you know when the numerator is the same number as the denominator? [The fraction equals 1.] or What do you know when the numerator is larger than the denominator? [The fraction names a number larger than one whole.] •Organize students into small groups and instruct them to work together on the Try It problems. Circulate among the groups and choose groups to share their ideas with the class. •Draw the models from problems 14 and 15 on the board. Bring up any questions that you heard students have when they were working and invite students to share ideas. Select groups to use the models on the board to explain how they found the equivalent fractions. •During the discussion ask questions such as: How do you know that the model shows 6 ? What does the 2 ·· fraction 18 tell you? [There are 18 parts and each 6 ·· use a fraction: 2 equals 8 4 ·· eight fourths . . 13 Explain how to find a fraction equivalent to a whole number. Possible answer: you look at how many parts are in one whole, and that is the denominator. then you count how many parts there are in all of the wholes together, and that is the numerator. try it use what you just learned to solve these problems. 14 Use the model to find a fraction equivalent to 3. 15 Draw a model to show 3 5 18 . 6 ·· 6 35 2 ·· 155 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Try It Solutions 14 Solution: 6 ; Students may label each half and count six 1 s. 2 ·· 2 ·· 15 Solution: Students may count each 1 to get 18 or use 6 ·· 6 ·· multiplication (wholes that each have 6 equal parts. That’s 18 sixths in all). whole has 6 parts or there are 3 wholes divided into Error Alert: Students who wrote 6 may have sixths. That’s 18 sixths in all.] Help students make counted 6 equal parts in the 3 wholes. They do not the connection to multiplication that the model understand the meaning of 6 , which means each of shows 3 wholes that each have 6 equal parts, which the 3 wholes is divided into halves and that there are is 18 parts in all. 6 halves in the 3 wholes. 6 ·· 2 ·· SMP Tip: Discuss with students how important it is to communicate clearly and precisely when explaining how to find an equivalent fraction to a whole. Encourage them to use precise math terms, such as numerator, denominator, and equivalent when sharing their thinking (SMP 6). 176 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 4: Modeled Instruction Lesson 17 At a Glance Part 4: Modeled instruction Students explore different ways to write a whole number as a fraction with a denominator of 1. Lesson 17 read the problem. then explore different ways to write a whole number as a fraction with a denominator of 1. Step By Step Justin picked 4 green peppers from his garden. He did not cut them into pieces. How can you write 4 as a fraction to show Justin’s green peppers? •Explain to students that they will now explore another way to write a whole number as a fraction. Picture it you can use models to help you write a whole number as a fraction with a denominator of 1. •Read the problem at the top of the page as a class. Ask students to picture the 4 whole green peppers in their mind. Direct their attention to the models shown in Picture It and explain that each circle stands for one green pepper. Each circle stands for 1 green pepper. They are not divided into pieces, so each whole is made of one part. Model it •Ask student if each whole pepper is divided into you can use a number line to help you write a whole number as a fraction with a denominator of 1. smaller parts. [No] Write the fraction 4 on the board. 1 ·· This number line shows whole numbers on the top and fractions on the bottom. Explain that 4 is the numerator because there are 4 wholes with one part each. Point out that the 0 1 2 3 4 0 1 1 2 1 3 1 4 1 Notice that each whole number has an equivalent fraction. The spaces between whole numbers are not divided into parts. Each whole number is made of one part, so the denominator is 1. denominator tells us the number of parts in each whole, which is one part. Tell students to say “four wholes” as they look at the fraction on the board. •Draw the number line in Model It on the board. 156 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Explain that the numbers on the top of the line are Copying is not permitted. whole numbers. Ask students if the whole numbers are shown with any smaller parts. [No] Write the fractions ( 1 , 2 , etc.) under the whole numbers on 1 ·· 1 ·· the number line. •Emphasize that the fraction 1 is equivalent to 1 ·· one whole, that 2 is equivalent to 2, 3 is equivalent to 3, etc. 1 ·· 1 ·· •For a quick assessment, ask students to write the fraction for 3 wholes on their paper or white board Mathematical Discourse •How could you show the fraction for 2 green peppers using the number 1 in the fraction? 2 1 ·· Concept Extension •Some students may have difficulty understanding and hold it up. Look for students to write 3 . Ask 1 ·· the meaning of a fraction with 1 in the them to explain to their partner what the numerator denominator. Write the fraction 2 on the board. and denominator tells them in the fraction. Have Remind them that 2 is made up of 2 copies of 1 . students share. Write “ 2 ” on the board. Explain that the 1 means 4 ·· 4 ·· 4 ·· 1 ·· there is only one part in the whole or that it is just one whole. Point out that the 2 in the numerator tells us that there are 2 copies of 1 whole, or 2 . 1 ·· L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 177 Part 4: Guided Instruction Lesson 17 At a Glance Students revisit the problem on page 156 and discuss the meaning of the 1 in fractions that are equivalent to a whole number. They apply this thinking to find fractions that are equivalent to other whole numbers. Part 4: guided instruction Lesson 17 connect it now you will solve the problem from the previous page. 16 Explain how you know each whole only has 1 part. the wholes are not divided into parts, so there is only 1 part. Step By Step •Work through the Connect It problems together. Ask students to discuss problem 21 with a partner, write a response and share ideas. Expect students to share that the 1 tells us the whole is one whole part (not divided into smaller parts) and the numerator tells the number of wholes that are shaded or are represented. •Ask students to work with a partner to discuss and respond to the Try It problems. Invite a student to explain their reasoning behind each response. 4 17 How many parts do the 4 green peppers make? 18 What does the numerator of a fraction show? how many parts you have 19 What does the denominator of a fraction show? how many parts in a whole 20 Write a fraction equivalent to 4. 4 number of parts 1 Remember: ·························· number of equal parts in a whole 2 1 ·· 21 Explain how to write a whole number as a fraction with a denominator of 1. Why does this work? Possible answer: Write the whole number as the numerator and use 1 for the denominator. the whole number is the number of parts. the denominator is the number of parts in the whole, which is 1. try it use what you just learned to solve these problems. 22 Use the model to find a fraction equivalent to 6. 6 1 ·· 65 23 Draw a model to show 5 5 5 . 1 ·· 157 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Try It Solutions 22 Solution: 6 5 6 . 1 ·· Error Alert: Students who wrote 1 are confused 6 ·· about how to write a fraction for 6 wholes and do not understand the meaning of 6 . 1 ·· 23 Solution: See possible student work above. 178 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Part 5: Guided Practice Lesson 17 Part 5: guided Practice Lesson 17 study the model below. then solve problem 24–26. Student Model The student used solid lines to show fourths and dotted lines to show eighths. Caleb and Hannah bought two melons that are the same size. Part 5: guided Practice Lesson 17 25 Show two fractions that are equivalent to 5. There will be 5 wholes in all. Think about how many parts will be in each whole. Show your work. Possible student work using models: Caleb cut his into fourths. Hannah cut hers into eighths. Hannah ate 4 of her melon, and Caleb ate an equal amount of 8 ·· his melon. What fraction did Caleb eat? Look at how you could show your work using a model. Pair/share Pair/share How could you solve this problem using a number line? How many thirds are in 1 whole? How many eighths are in 1 whole? Solution: Solution: caleb ate 2 of his melon. 2 ··· 3 ··· 26 Kaia ate 3 of a banana. Zoie ate an equivalent amount. Which 6 ·· 24 Matt says 3 is equivalent to 1. Elisa says 8 is equivalent to 1. 8 ·· 3 ·· Who is correct? 1 3 c 2 3 8 8 5 8 ·· 2 ·· 3 3 Landon chose a as the correct answer. How did he get that answer? Possible answer: he found a fraction that is equivalent Pair/share Does Landon’s answer make sense? to 2 , not 3 . 0 1 2 3 4 5 6 7 8 8 8 8 2 3 ·· D 1 1 8 Look at where 3 is on a 6 ·· number line. What other fraction could be shown at the same point? 3 ·· 0 Pair/share answer. b 1 0 fraction shows how much Zoie ate? Circle the letter of the correct a 1 Show your work. 0 158 Possible answer: 10 ; 15 4 ·· Possible student work using number lines: What is another fraction that is equivalent to 1? How did you decide what denominators to use in your fractions? 6 ·· 8 8 6 ·· Solution: they are both correct. L17: Find Equivalent Fractions 159 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. At a Glance ©Curriculum Associates, LLC Copying is not permitted. 24 Solution: Both students are correct; The student may Students use models and number lines to solve problems involving fractions that are equivalent to whole numbers. draw 2 equal rectangles, dividing one into thirds Step By Step equivalent. (DOK 1) •Ask students to solve the problems individually and to label the fractional parts in their drawings. •When students have completed each problem, have them Pair/Share to discuss their solutions with a partner or in a group. 8 shaded equal parts to show that both 8 and 3 are 8 ·· 3 ·· 25 Solution: Possible answers 10 and 15 or 10 and 20 ; 2 ·· 3 ·· 2 ·· Students use two same-sized models to show 4 ·· 5 wholes that are each divided into two parts and three parts or two parts and four parts. (DOK 1) 2 6 Solution: D; Identify the fraction in which both the numerator and denominator can be multiplied by Solutions Ex Students knew that Caleb ate pieces cut into fourths, so they looked at the number of fourths that 4 covered 1 2 2. In this problem, students must 8 ·· and shading the whole. The other rectangle shows 4 ·· look for larger-sized pieces that cover the same amount in the model. L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. the same number to equal 3 . 6 ·· Explain to students why the other two answer choices are not correct: B and C are not correct because the student does not understand that 3 out of 6 parts is the same amount as 1 out of 2 parts. (DOK 3) 179 Part 6: Common Core Practice Part 6: common core Practice Lesson 17 Solve the problems. 1 2? Which fraction shown is equivalent to } 6 B C B C D 0 1 1 2 1 3 1 4 1 0 1 1 2 1 3 1 4 1 0 1 4 2 4 3 4 1 0 1 4 2 4 3 4 4 4 b. D c. 3 } 1 1 } 3 4 } 1 6 } 3 d. 5 Lesson 17 For numbers 4a–4d, choose Yes or No to indicate whether each number graphed on the number line represents one whole. a. Which fraction is equivalent to 3? A 3 Part 6: common core Practice 4 A 2 Lesson 17 3 Yes No Yes 3 No 3 Yes No 3 Yes No Use the number line below to find a fraction equivalent to 3. Show your work. Possible student work using a number line: 0 Look at point P on the number line. P 0 0 1 a. 0 1 0 1 b. c. 0 3 is equivalent to Answer Look at number lines 3a–3c. Is the point on each number line equal to the number shown by point P? Choose Yes or No. 3 Yes No Yes 3 No Yes 3 No 6 1 1 3 2 3 3 3 2 4 3 5 3 6 3 3 7 3 8 3 9 3 9 3 ·· 1. Draw a model to find a fraction equivalent to } 4 Show your work. 2 1 is equivalent to } 4 Answer Possible student work using a model: 8 ·· 1 self check Go back and see what you can check off on the Self Check on page 131. 160 L17: Find Equivalent Fractions L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. ©Curriculum Associates, LLC Copying is not permitted. At a Glance 4Solution: a. Yes; b. No; c. Yes; d. Yes (DOK 2) Students answer questions about fractions that are equivalent to whole numbers that might appear on a mathematics test. 5Solution: 9 ; See possible student work above. (DOK 1) 3 ·· 6Solution: 2 ; See possible student work above. (DOK 1) Solutions 161 8 ·· 1Solution: D; Students see that if they divide each third into two equal parts, they will get 2 . (DOK 1) 6 ·· 2Solution: A; Students understand that the numerator shows that there are 3 wholes and the denominator shows that each whole is one whole part. (DOK 1) 3Solution: a. Yes; b. No; c. No (DOK 2) 180 L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. Differentiated Instruction Lesson 17 Assessment and Remediation •Ask students to show a fraction that is equivalent to 4 using a number line. Provide a number line from 0 to 4 1 ·· showing halves (no fraction labels) and whole numbers labeled. •For students who are struggling, use the chart below to guide remediation. •After providing remediation, check students’ understanding. Ask students to use a number line to show a fraction that is equivalent to 3 . Provide a number line showing thirds (no fraction labels) and whole numbers 1 ·· labeled. If the error is . . . Students may . . . To remediate . . . students label the not understand how to Ask students to circle the whole numbers on the number line. Have halves but do not show that two fractions them count by 1 s and label each half ( 1 , 2 , 3 , 4 , etc.) Review with clearly show that 4 on a number line are students the meaning of 4 . Be sure students understand that the and 8 are on the equivalent or are denominator names the size of the parts, which are one whole in size, same point on the confused as to what the and that the numerator tells how many there are of those wholes. number line and, fraction 4 means. 1 ·· Asks students to write the fraction for the whole numbers on the top 1 ·· 2 ·· therefore, are 2 ·· 2 ·· 2 ·· 2 ·· 2 ·· 1 ·· part of the number line ( 1 , 2 , 3 , 4 ). Direct students to put a point at 4 1 ·· 1 ·· 1 ·· 1 ·· 1 ·· and explain in words that 4 and 8 name that same point. equivalent. 1 ·· 2 ·· Hands-On Activity Challenge Activity Explore equivalent fractions with differently shaped parts. Explore equivalent fractions with differently shaped parts. Materials: graph paper with 4 3 4 squares outlined Materials: graph paper with 4 3 4 squares Have students work in pairs to explore different ways outlined This activity is an extension of the to divide the 4 3 4 square into two equal areas to Hands-On activity. Instead of having students find show the fraction 2 . Students will discover that each 2 ·· half may be a different shape, but they cover the same area or amount of the square. When a student finds a new way to divide the 4 3 4 square into two equal areas, have them share with the class. Ask students how they can prove that each ways to show 1 , have students explore ways to 2 ·· divide their large square into equal parts to show 4 . 4 ·· Again, students will discover that each 1 may be a 4 ·· different shape, but each 1 covers the same area 4 ·· or amount of the square. They will also see that each 1 is equivalent to 4 . 4 ·· 16 ·· half is really 1 of the square. Students should 2 ·· recognize that each 1 should have 8 of the 16 smaller squares. 2 ·· L17: Find Equivalent Fractions ©Curriculum Associates, LLC Copying is not permitted. 181