CHAPTE R 8 Decimals and Fractions connectED.mcgraw-hill.com The BIG Idea Investigate How are decimals and fractions connected? Animations Vocabulary Math Songs Multilingual eGlossary Learn Personal Tutor Virtual Manipulatives Audio Foldables Practice Self-Check Practice eGames Worksheets Assessment Make this Foldable to help you organize information about decimals and fractions. Begin with one sheet of 1 8 _ ” × 11” paper. 2 a ls cim De alent Equiv tions rac imals F ions and Dec ract F New Vocabulary decimal decimal a number that uses place value, numbers, and a decimal point to show part of a whole 0.3 6 004A 112056 Key Vocabulary English Español fracciones equivalentes equivalent fractions maximo común divisor greatest common factor forma reducida simplest form número mixto mixed number 380 When Will I Use This? Nicholas in Flying Feat Boy, this paper airplane contest is going to be fun, Mr. Grey! Right, Nicholas! Each student will use their tape measure and I’ll write down the distance their plane flies. Your turn, Olivia. OK! Wow! How far did it go? Julian and Teresa, how about you? My airplane went 7 –34 feet. Sweet! 5 –12 feet. My turn! Good throw, Ethan! 6 –13 feet! Mine went 6 –14 feet. Your turn, Nicholas. Hope my airplane goes the farthest. Your Tthuiisrn! You will sollve err. teer problem in the chap Decimals and Fractions 381 Are You Ready You have two options for checking Prerequisite Skills for this chapter. for the Chapter? Text Option Take the Quick Check below. Write a fraction to describe the part that is green. 1. 2. 3. 5. eight-tenths 6. twenty-hundredths Write each as a fraction. 4. four-tenths 7. Measurement On Tuesday, seven tenths of an inch of rain fell. Write the amount of rain that fell as a fraction. Algebra Copy and complete. 8. 9. 4 __ = ___ 5 10 1 __ = ___ 5 10 6 4 10. In Salvador’s aquarium, ___ of the fish are yellow, and ___ are blue. 10 10 Are there more blue or yellow fish in Salvador’s aquarium? Explain how you know. Online Option 382 Decimals and Fractions Take the Online Readiness Quiz. Multi-Part Lesson 1 Decimals A PART I will explore decimals. Materials IVOESFEUIT UIPVTBOEUIT %FDJNBMT UFOUIT 0OFT UFOT Workmat 6 POFT C D E Place Value Through Tenths and Hundredths Main Idea IVOESFET B A decimal is a number that uses place value and a decimal point to show part of a whole. The place-value chart shows how decimals are part of the base-ten system. You can use a place-value chart and models to represent decimals. Hundreds Tens Ones Tenths Hundredths hundredths grid colored pencils ÷10 ÷10 ÷10 Use a place-value chart to show seven-tenths. U Step 1 Use a place-value chart. Write 7 in the tenths column. Hundreds Tens Ones Tenths Hundredths Get ConnectED GLE 0406.2.1 Understand place value of numbers from hundredths to the hundred-thousands place. ÷10 0 Step 2 Use a model. Step 3 Write the decimal. 0.7 decimal point 7 tenths place So, seven-tenths can be written as 0.7. Lesson 1A Decimals 383 Model forty-five hundredths. Write the decimal. M Step 1 Use a place-value chart. Write 4 in the tenths column and 5 in the hundredths column. Hundreds Tens Ones Tenths Hundredths 0 Step 2 4 5 Use a hundredths grid. Shade 45 of the 100 parts to show 45 hundredths. Step 3 Write the decimal. 0.45 So, forty-five hundredths can be written 0.45. About It 1. Describe the difference between the decimals two-tenths and two-hundredths. 2. Use a hundredths grid to model the decimals in Exercise 1. Identify the greater decimal. and Apply It Write a decimal for each shaded part. 4. 3. 5. Write each decimal. 6. two-tenths 7. twenty-five hundredths 8. forty-nine hundredths 9. seventy-three hundredths Model each decimal. 10. 0.37 14. E 11. 0.51 WRITE MATH Explain how to use a place-value chart to write seventeen-hundredths. 384 3 12. 0.88 Decimals and Fractions 13. 0.9 Multi-Part Lesson 1 Decimals PART A Main Idea I will model and describe tenths as part of the base-ten system. Vocabulary V decimal B C D E Tenths In the previous lesson, you used parts of a whole to show the place value. A decimal is a number that uses place value, numbers, and a decimal point to show part of a whole. A tenth is one of ten equal parts. tenths Write Tenths W Get ConnectED GLE 0406.2.1 Understand place value of numbers from hundredths to the hundred-thousands place. SPI 0406.2.1 Read and write numbers from hundredths to hundredthousands in numerals and in words. HORSES Lorena and Rebecca went to 10 horseback riding lessons. Three of the lessons were outside the barn. What part of horseback riding lessons was spent outside? Step 1 Find the parts. There were 10 horseback riding lessons. Three of the 10 lessons were spent outside. Step 2 Model the parts. Use a base-ten model to show three out of ten, or three-tenths. Read three-tenths Write 0.3 So, 0.3 of the horseback riding lessons were outside. Lesson 1B Decimals 385 Write Tenths W CAMPING A campground has 10 campsites. Eight of the campsites have campers. The rest are empty. What part of the campground is empty? If eight out of ten campsites have campers, then two out of ten campsites do not have campers. You can use a place-value chart to write two out of ten, or two-tenths. Hundreds Tens Ones Tenths Hundredths Thousandths 0 2 So, 0.2 of the campground is empty. Describe Tenths Use words to describe 0.7. Seven-tenths means seven out of ten equal parts. So, 0.7 can be described as seven out of ten. Model and write each decimal decimal. SSee EExamples l 1 andd 2 1. four out of ten 2. eight-tenths 3. two-tenths Describe each decimal. See Example 3 4. 0.5 5. 0.1 7. A flower has ten petals. During a storm, five of the petals fall off. Write a decimal to show what part of the petals is left. 9. 386 E 6. 0.3 8. A house has ten windows. During spring cleaning, eight windows were washed. Write a decimal to show what part of the windows still needs to be cleaned. TALK MATH Explain why dimes could be used to model tenths. Decimals and Fractions % )# E # T4 IC !C 2A 0R P EXTRA Begins on page EP2. Model and write each decimal. See Examples 1 and 2 10. one out of ten 11. five out of ten 12. four-tenths 13. seven-tenths 14. nine-tenths 15. eight-tenths Describe each decimal. See Example 3 16. 0.2 17. 0.6 19. Emilio had a math quiz today. He answered nine of the ten questions correctly. Write a decimal to show what part of the quiz Emilio answered correctly. 21. Jasmine had ten pennies in her pocket. Some fell through a hole in her pocket. Below are the pennies she still has in her pocket. Write a decimal to show how many pennies she lost. 18. 0.9 20. Cody’s dog had ten chew toys. Cody took six toys outside for his dog. Write a decimal to show what part of the toys is still inside. 22. There were ten goldfish in the aquarium below. Some fish were moved to a new aquarium. Use the picture to write a decimal to show how many fish are still in the original aquarium. Measurement Meteorologists reported the amount of rainfall for 4 weeks in April. Use the table to answer the following questions. 23. Write each amount of rainfall in decimal form. Rainfall (in inches) April Week Week Week Week 1 2 3 4 eight-tenths four-tenths nine-tenths seven-tenths 24. Model the decimal described in week 1. 25. OPEN ENDED Write a decimal whose value is greater than five-tenths. 26. E WRITE MATH Write a real-world problem with 0.8 as the answer. Lesson 1B Decimals 387 Multi-Part Lesson 1 Decimals PART A Main Idea I will describe hundredths as part of the base-ten system. B C D E Hundredths A hundredth is one of one hundred equal parts. Vocabulary V hundredths thousandths Get ConnectED GLE 0406.2.1 Understand place value of numbers from hundredths to the hundred-thousands place. SPI 0406.2.1 Read and write numbers from hundredths to hundredthousands in numerals and in words. 1.0 one 0.1 one-tenth 0.01 one-hundredth Write Hundredths Drew has a 100-piece puzzle. There are four corner pieces in the puzzle. What part of the puzzle is corner pieces? Four of the 100 puzzle pieces are corner pieces. 4 of 100 parts are shaded. Read four-hundredths Write 0.04 So, 0.04 of the puzzle pieces are corner pieces. 388 Decimals and Fractions Write Hundredths Tiffany has the coins shown. What part of a dollar are the W coins worth? Step 1 Count the parts. $1 = 100¢ 10¢ Step 2 11¢ 11 12¢ 12 13¢ 13 14¢ 14 Compare the parts to the whole. Each cent is one hundredth, or 0.01, of a dollar. Fourteen-hundredths is 0.14 of a dollar. So, the coins are 0.14 of a dollar. Write each decimal. decimal SSee EExample l 1 1. 2. 3. Write a decimal for each part of a dollar shown. See Example 2 4. 5. 6. A movie theater has 100 seats. Seventy-eight of the seats are full. What decimal shows the part of the seats that is full? 7. E TALK MATH Explain why coins can be used to model decimals. Lesson 1C Decimals 389 EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Write each decimal. See Example 1 8. 9. 10. 11. 12. 13. Write a decimal for each part of a dollar shown. See Example 2 14. 15. 16. 17. 18. Emma earned eighty-nine out of 100 points on a math test. What decimal shows the part of the points that Emma earned? 19. A department store had one hundred teapots. Six of the teapots were sold. What decimal represents the teapots that are left? 20. Darnell inserted the coins shown into a vending machine. What part of a dollar are the coins? 21. Bena received the coins shown as change after buying pencils at the school store. What part of a dollar are the coins? 390 Decimals and Fractions 22. OPEN ENDED Write a real-world problem that results in an answer of 0.72. 23. CHALLENGE What is the least number of coins needed to make 0.90 of one dollar? Which coins are used? 24. E WRITE MATH Write a decimal to represent the models below. Explain. Decimals A whole number can be divided into 1,000 equal parts called thousandths . Thousandths are smaller than hundredths. Write Thousandths W CARNIVALS A school carnival sells 1,000 tickets. On Saturday, 415 of the tickets are sold. The rest are sold on Sunday. What part of the tickets is sold on Sunday? Subtract the number of tickets sold on Saturday. 1,000 – 415 = 585 On Sunday, 585 of the 1,000 tickets were sold. Read five hundred eighty-five thousandths Write 0.585 So, 0.585 of the tickets were sold on Sunday. Write each decimal. 25. three hundred forty-two thousandths 26. twenty-six thousandths 27. five-thousandths 28. An apple orchard can produce about 1,000 apples. If 35 of the apples are rotten, what part of the apples is not rotten? 29. E WRITE MATH Explain why 0.040 is not the same as 0.004. Lesson 1C Decimals 391 Multi-Part Lesson 1 Decimals PART A Main Idea I will write decimals greater than one. Get ConnectED GLE 0406.2.1 Understand place value of numbers from hundredths to the hundred-thousands place. SPI 0406.2.1 Read and write numbers from hundredths to hundredthousands in numerals and in words. B C D E Decimals Greater Than One You have described decimals that have values that are less than one whole. The value of decimals can also be greater than one whole. These numbers contain a whole number and a decimal part. Model Decimals Model 5.02. Since the least place value is the hundredths place, use hundredths grids to model 5.02. Step 1 Model the whole number. Since the whole number is 5, shade 5 hundredths grids. Step 2 Model the decimal. Since there are two-hundredths, shade 2 squares of a sixth hundredths grid. two-hundredths = 2 out of 100 squares shaded So, 5.02 represents the whole number five and two hundredths of one whole. 392 Decimals and Fractions Representing Decimals Words Examples Standard Form the usual way to write a number using digits Word Form a way to write a number using words Expanded Form a way to write a number showing the value of each digit 6.25 six and twenty-five hundredths 6 + 0.2 + 0.05 Write Decimals Hundredths Expanded form: 8 + 0.7 + 0.05 Tenths Standard form: 8.75 Ones Write each digit of eight and seventy-five hundredths in a place-value chart. 8 7 5 Thousandths A flamingo weighs about eight and seventy-five hundredths pounds. Write eight and seventy-five h hundredths in standard and expanded form. Read and Write Decimals To write decimals in word form, use the word and for the decimal point. W Write sixteen and one hundred twenty-eight thousandths in standard and expanded form. Write each digit of sixteen and one hundred twenty-eight thousandths. Standard form: 16.128 Expanded form: 10 + 6 + 0.1 + 0.02 + 0.008 Lesson 1D Decimals 393 Model each decimal l 1 decimal. SSee EExample 1. 2.4 2. 5.13 3. 9.07 4. Write seven and fifty-three hundredths in standard and expanded form. 5. E TALK MATH Describe how to write eighty-two and three-hundredths in standard form. See Examples 2 and 3 EXTRA % )# E # T4 IC !C 2A PR 0 Begins on page EP2. Model each decimal. See Example 1 6. 1.6 7. 3.9 8. 4.27 9. 7.69 10. 11.37 11. 26.46 Write each decimal in standard and expanded form. See Examples 2 and 3 12. five and thirty-seven hundredths 13. eight and ninety-three hundredths 14. ten and sixty-one hundredths 15. thirteen and forty-six hundredths For Exercises 16–18, use the table at the right. 16. Write the length of a tibia in expanded form. 17. Write the length of the shortest bone in word form. Longest Bones in the Human Body Bone Length (in.) Femur (thigh bone) Humerus (upper arm bone) Seventh Rib 14.35 Tibia (shin bone) 16.94 18. Write the length of the longest bone in word and expanded form. For Exercises 19–21, use the table at the right. 19. Write the length of a King Cobra in expanded form. Facts About Cobras 20. Write the length of King Cobra fangs in word form. • The fangs of a King Cobra can be up to 1.25 cm long. 21. Write the distance a black-necked cobra can spit venom in word form. 394 Decimals and Fractions • King Cobras have been found up to 5.5 m long. • The black-necked cobra can spit venom 2.4 m. 19.88 9.45 22. OPEN ENDED Write two decimals that are equivalent to 3.6. Explain. 23. E WRITE MATH Explain how the word form of a decimal can help you write the standard form of the decimal. Test Practice 24. Which model represents 2.01? (Lesson 1D) A. B. C. D. 25. Lydia has five pizzas. Each pizza has ten slices. Four of the pizzas are whole. One pizza has only 8 slices left. Which decimal describes Lydia’s pizzas? (Lesson 1D) F. 4.08 H. 4.8 G. 4.2 I. 5.4 26. Each box holds one hundred paper clips. There are two full boxes. The third box has only 24 paper clips. Which decimal describes the boxes of paper clips? (Lesson 1D) A. 2.24 C. 3.24 B. 2.42 D. 3.42 Write each decimal. (Lesson 1C) 27. two-hundredths 28. nineteen-hundredths 29. forty-eight hundredths 30. two hundred sixty thousandths 31. A pronghorn antelope can run about 0.88 mile per minute. Use a hundredths grid to model 0.88. (Lesson 1C) To assess partial mastery of SPI 0406.2.1, see your Tennessee Assessment Book. 395 Multi-Part Lesson 1 Decimals PART A Main Idea I will compare and order decimals. Get ConnectED B C D E Compare and Order Decimals To compare decimals, you can use a number line or place value. SPI 0406.1.2 Compare decimals using concrete and pictorial representations. SPI 0406.2.6 Use the symbols <, >, and = to compare common fractions and decimals in both increasing and decreasing order. SCORES The table shows the results from a skateboarding competition. Who has the higher score, Doria or Elise? Doria has a score of 79.7, while Elise has a score of 79.5. One Way: 79.0 79.2 Number Line Elise Doria 79.5 79.7 79.4 79.6 79.8 80.0 79.7 is to the right of 79.5. So, 79.7 > 79.5. So, Doria has the higher score. 396 Decimals and Fractions Tenths Line up the decimal points. Then compare the digits in each place-value position. In the tenths place, 7 > 5. So, 79.7 is greater than 79.5. Ones Place Value Tens Another Way: 7 9 7 7 9 5 Order Decimals Everyday Use Order select items you want Order 9.86, 9.8, 9.92, and 9.09 from greatest to least. Math Use Order to arrange in a logical pattern Next, place zeros to the right of the last digit so all numbers have the same number of decimal places. First, line up the decimal points. Finally, compare and order using place value. 9.86 9.86 9.92 9.8 9.80 9.86 9.92 9.92 9.80 9.09 9.09 9.09 The order from greatest to least is 9.92, 9.86, 9.8, and 9.09. Compare > < = See Example 1 Compare. Use >, <, or =. 1. 0.2 0.6 2. 12.07 1.207 3. 5.60 5.6 Order from greatest to least. See Example 2 4. 3.2, 4.5, 3.9, 4.1 5. 0.12, 1.2, 1.21, 12.0 6. $6.52, $5.62, $6.50, $5.60 Use the number line to compare and order each set of decimals from least to greatest. 4 7. 5.7, 5.2, 4.7, 4.2 4.5 5 5.5 6 8. 4.2, 4.8, 6.2, 5.8 9. Measurement Four friends are going to different summer camps. The table shows the distance between each camp and their hometowns. Order the distances from least to greatest. 10. E TALK MATH Tell how to order 5.5, 5.3, 5.4, and 5.0 from greatest to least. Traveling to Camp Name Distance (mi) Bill 64.25 Sami 42.5 Latesha 64.87 Irena 42.35 Lesson 1E Decimals 397 EXTRA % )# E # T4 IC !C 2A PR 0 Begins on page EP2. Compare. Use >, <, or =. See Example 1 11. 0.74 7.4 12. 16.33 16.3 13. 0.56 0.58 14. 0.8 0.80 15. 1 0.09 16. 0.90 0.9 17. 82.6 82.60 18. 1.06 1.05 Order from greatest to least. See Example 2 19. $19.62, $19.56, $19.60 20. 0.5, 0.55, 0.6 21. 68.16, 81.6, 68.1 Use the number line to compare and order each set of decimals from least to greatest. 6 7 8 9 22. 6.3, 8.1, 7.5, 7.7 23. 8.4, 7.9, 8.8, 8.6 24. 7.5, 6.2, 7.75, 6.25 25. 7.8, 8.25, 8.2, 8.50 26. Marlon averages 5.6 rebounds per game. Tina averages 5.9 and Omar averages 4.3 rebounds per game. Who averages the most rebounds? Explain. 27. Measurement Desiree ran the 100-meter dash four times. Her times were 16.25, 15.36, 16.55, and 15.23 seconds. What was her slowest time? 28. NUMBER SENSE What number is halfway between 4.36 and 4.48 on a number line? 29. FIND THE ERROR Ashley wrote 3 decimals in order from least to greatest. Find and correct her mistake. 6.27, 6.19, 6.29 30. E WRITE MATH Write a real-world problem about comparing and ordering decimals. 398 To assess mastery of SPI 0406.1.2, see your Tennessee Assessment Book. Multi-Part Lesson 2 Fractions A PART B C D E F Equivalent Fractions Main Idea I will explore equivalent fractions. Like decimals, fractions are used to show part of a number. Fractions that represent the same part of a number are equivalent fractions. Materials Identify two fractions that are equivalent to fraction tiles 1 4 1 1 3 Step 1 1 2 1 Model _. 1 3 1 _ fraction tile 3 1 to show _ . Get ConnectED 3 1 3 Start with 1 whole. Then, use the _1 . 3 SPI 0406.2.5 Generate equivalent forms of common fractions and decimals and use them to compare size. Step 2 1 Find a fraction equivalent to _1 . 3 1 3 1 Using _ fraction 6 tiles, place them below the 1 _ fraction tile. 1 6 1 6 3 How many 1 _ fraction tiles 6 are used? Step 3 1 Find another fraction equivalent to _1 . 1 3 3 1 Use _ fraction 12 tiles to equal the length of the 1 _ fraction tile. 3 1 6 1 6 1 1 1 1 12 12 12 12 1 Count the number of _ fraction tiles. 12 1 2 4 So, _, _, and _ are equivalent fractions. 3 6 12 Lesson 2A Fractions 399 IIdentify equivalent fractions. Step 1 Step 2 Draw three identical number lines that show zero and one. 0 1 0 1 0 1 2 4 Notice that _ = _ = _. 8 1 1 4 0 Divide the first number line into fourths. Divide the second number line into eighths. Divide the third number line into sixteenths. 4 0 1 8 2 4 2 8 3 8 4 8 3 4 5 8 6 8 4 4 7 8 8 8 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 About It 1 1. Algebra Copy and complete _ = _ = _. 3 9 15 3 2. Refer to Activity 2. Find two fractions equivalent to _. 4 and Apply It Determine whether the fractions are equivalent. Write yes or no. Use fraction tiles or number lines. 6 2 3. _ and _ 4 12 6 5 4. _ and _ 8 10 3 2 5. _ and _ 3 5 9 3 6. _ and _ 12 Find two equivalent fractions for each fraction. Use fraction tiles or number lines. 1 7. _ 5 11. 400 E 2 8. _ 6 4 9. _ 8 2 10. _ 12 WRITE MATH Explain what it means for two fractions to be equivalent. Decimals and Fractions 4 Multi-Part Lesson 2 Fractions PART A Main Idea I will find equivalent fractions. B C D E F Equivalent Fractions 4 1 The fraction models show that _ is the same as _. Fractions 2 8 Vocabulary V that represent the same amount are equivalent fractions . equivalent fractions 1 Get ConnectED 1 2 SPI 0406.2.5 Generate equivalent forms of common fractions and decimals and use them to compare size. Also addresses GLE 0406.1.1, GLE 0406.3.1. Prefixes The prefix equi- means equal. 1 8 1 8 1 8 1 8 Find Equivalent Fractions FISH Allie has 8 fish in an aquarium. Four fish are _4 of the fish are green. Find three fractions 8 4 that are equivalent to _. green. So, 8 You can use multiplication or division. One Way: Multiply 8 _ 8 × 2 = 16 Multiply the numerator and the denominator by the same number, 2. 4× 2 ___ Another Way: Divide Divide the 4÷ 2 2 _ _ numerator = 8÷2 4 2÷ 2 _ _1 4÷2 = 2 and the denominator by the same number, 2. 8 2 1 4 So, _, _, and _ are equivalent to _. 16 4 2 8 Lesson 2B Fractions 401 Write the fraction for the part that is shaded shaded. Then find an equivalent fraction. See Example 1 1. 2. 3. Find an equivalent fraction for each fraction. See Example 1 1 4. _ 4 4 5. _ 1 6. _ 6 10 10. 9. Javier has 4 juice boxes. Three are grape flavored. Write two fractions that describe the part of the juice boxes that is grape. 1 8. _ 3 8 7. _ 5 E TALK MATH Tell why 3 _ 6 _ , and 4 8 9 _ are equivalent fractions. Give an 12 example of another set of three equivalent fractions. EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Write the fraction for the part that is shaded. Then find an equivalent fraction. See Example 1 11. 12. 13. 14. 15. 16. Find an equivalent fraction for each fraction. See Example 1 2 17. _ 2 18. _ 6 19. _ 2 20. _ 2 21. _ 6 22. _ 1 23. _ 9 24. _ 1 25. _ 12 26. _ 7 8 5 2 10 27. A roller coaster has 16 cars. Six of the cars are green. Write two fractions for the part of the cars that is green. 402 Decimals and Fractions 18 12 6 3 20 1 28. Measurement Lucas ran _ mile. 2 4 Ayana ran _ mile. Did they run the 6 same distance? Explain. Algebra Find the value of x. 3 12 29. _ = _ x 4 x 2 30. _ = _ 5 8 x 31. _ = _ 25 12 8 1 32. _ = _ x 64 3 Science The state animal of Michigan is the white-tailed deer. Female deer, called does, usually have 1 to 3 young at a time. Young deer are called fawns. The male deer, called bucks, grow antlers in the spring. 33. Suppose 10 deer are traveling together. If 4 of them are does and 3 are fawns, what fraction represents the number of bucks? Write another fraction that represents this number. 34. A doe has 3 fawns. If one of the fawns is male, what fraction of the fawns is female? Write a fraction equivalent to this fraction. 2 35. OPEN ENDED Write a fraction equivalent to _. Write a fraction 5 3 equivalent to _. Which fraction represents a greater number? 6 Explain. 36. FIND THE ERROR Julian is finding a fraction equivalent to _. 18 Find and correct his mistake. 6 6 ÷ 3 = __ 3 _______ 18 ÷ 3 6 25 37. CHALLENGE Identify a fraction that is equivalent to _. 100 38. E WRITE MATH Can you always find an equivalent fraction for a fraction? Explain. Lesson 2B Fractions 403 Multi-Part Lesson 2 Fractions PART A B C D E Problem-Solving Strategy: F Make a Model Main Idea I will solve problems by making a model. Brandi and her mom are at a pet store. The pet store has 15 reptiles. One third of the reptiles is turtles. Two are snakes, and the rest are lizards. How many of each reptile are there? Understand What facts do you know? • There are 15 reptiles at the store. • Two are snakes. k • One third is turtles. • The rest are lizards. What do you need to find? • Find the number of each reptile. Plan Make a model to solve the problem. Solve • Draw 15 circles. Since the 1 fraction _ is used, place the 3 circles in 3 equal groups. 1 • To show the turtles, shade _ 3 of the circles, that is, one of the three equal groups. So, there are 5 turtles. There are 2 snakes, so shade 2 circles to show the snakes. turtles • There are 8 circles not shaded. This is the number of lizards. So, there are 5 turtles, 2 snakes, and 8 lizards at the pet store. Check Look back. 5 turtles + 2 snakes + 8 lizards = 15 reptiles. The pet store has 15 reptiles. So, the answer is correct. SPI 0406.2.10 Solve contextual problems using whole numbers, fractions, and decimals. 404 Decimals and Fractions snakes Refer to the problem on the previous page. 1. Explain why you used 15 circles. 1 2. You know that _ of the reptiles are 3. If the pet store had 24 reptiles, how many of the reptiles would be lizards? 3 turtles. Explain why 5 circles were shaded to show the number of turtles. 4. Check your answer to Exercise 3. How do you know that it is correct? EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Solve. Use the make a model strategy. 5. Measurement There are three trees in a backyard. The second tree is half as tall as the first. The third tree is taller than the second tree and shorter than the first tree. The total height of the trees is 24 feet. What is the height of each tree? 10 ft x y 8. There are 22 students in Ms. Lane’s class. Half of them packed their lunches. Eight students are buying pizza. The rest are buying salads. How many students are buying salads? 9. Measurement The table shows how long Adam and Kenya rode their bikes. Who biked more minutes? How many more minutes? Biking Schedule 6. Corey has 8 apples. Four are red, two are green, and the rest are yellow. Write two fractions that name the part of the apples that are yellow. 7. Emil bought his mom a dozen roses. Some of the roses are shown below. The rest are white. Of which color were there the most? What fraction of the roses were that color? Write an equivalent fraction. Name Time Spent Biking Adam 1 of an hour __ Kenya 15 minutes 3 10. There are 16 books on a shelf. One-fourth of the books are about animals. Two are adventure. The rest are mystery. How many are mystery books? 11. E WRITE MATH Look back at Exercise 10. Explain how you used the make a model strategy to solve the problem. Lesson 2C Fractions 405 Multi-Part Lesson 2 PART Fractions A Main Idea I will compare and order fractions. Get ConnectED B D C E F Compare and Order Fractions To compare fractions, you can use models, number lines, and equivalent fractions. SPI 0406.2.6 Use the symbols <, >, and = to compare common fractions and decimals in both increasing and decreasing order. Compare Fractions MEASUREMENT Ramon has an insect collection. The table shows the lengths of four insects in his collection. Which is longer, a field cricket or a whirligig beetle? You can use fraction models to 5 3 compare _ and _. 8 8 5 _ Field cricket 3 _ Whirligig beetle 8 8 5 3 The models show that _ > _. 8 8 So, the field cricket is longer than the whirligig beetle. Which is longer, a mosquito or lightning bug? 1 1 You need to compare _ and _. 4 0 0 1 4 2 4 1 2 3 4 1 1 2 1 _ Mosquito 1 _ Lightning bug 4 2 So, the lightning bug is longer than the mosquito. 406 Decimals and Fractions Order Fractions Order _2 , _1 , and _7 from least to greatest. 3 2 12 Number Lines One Way: Another Way: Use a number line. 0 0 12 1 7 12 _1 , _7 , _2 . 2 12 3 3 12 12 12 12 12 _1 < _7 < _2 2 2×6 Compare the numerators. Order from least to greatest. _6 , _7 , _8 1 1 2 0 Find equivalent fractions with the same denominator. 2×4 _ _8 _ _6 1×6 = = 3×4 1 2 3 Equivalent Fractions So, the order from least to greatest is _1 , _7 , _2 . 2 12 3 Compare. Use > , < , or =. SSee Examples Compare E l 1 andd 2 1. 2. 0 5 1 _ _ 8 1 4 0 8 1 6 2 4 2 6 1 3 4 3 6 4 6 5 6 1 1 1 _ _ 4 3 1 3. _ _ 4 6 3 3 4. _ _ 2 6 4 Order from least to greatest. See Example 3 3 2 4 5. _, _, _ 1 7 3 6. _, _, _ 16 8 4 8 6 8 1 7. Measurement Griff worked for _ of 3 3 an hour. Sasha worked for _ of an 12 8. E TALK MATH Explain how to compare 7 2 the fractions _ and _. 6 12 hour. Who worked for a longer time? Lesson 2D Fractions 407 EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Compare. Use > , < , or =. See Examples 1 and 2 9. 10. 7 4 _ _ 10 4 1 _ _ 10 8 4 2 6 3 6 12. 11. 0 1 3 0 1 6 2 3 2 6 3 6 4 6 5 6 1 0 1 0 1 1 6 8 5 2 _ _ 3 2 8 3 8 4 6 4 8 5 8 6 8 7 8 6 8 3 5 14. _ _ 8 4 15. _ _ 5 2 16. _ _ 4 1 17. _ _ 5 2 18. _ _ 3 3 5 9 1 5 4 _ _ 6 2 1 13. _ _ 6 1 5 6 5 6 10 2 8 10 3 Order from least to greatest. See Example 3 4 1 3 19. _, _, _ 3 2 7 20. _, _, _ 6 3 3 3 3 3 21. _, _, _ 4 3 8 22. Which meat makes up most of Mr. Collin’s sandwich? 10 4 5 23. Allison took a survey. Find the favorite weekend activity. Favorite Weekend Activities Activity 1 Decimals and Fractions Basketball 25. Suzanne practiced volleyball for _ 3 1 hour on Saturday and _ hour on 6 Sunday. Which day did she practice longer? 26. Measurement The table shows how much time each student needs to finish an art project. Does Simón need more or less time than Phil? Explain. 408 Mall ADMIT ONE ADMIT ONE 24. Aisha ate _ of the carrots in the bag. 4 3 Enrique ate _ of the carrots in the 12 bag. Who ate more carrots? Movie Fraction of Friends 2 6 1 4 5 12 2 Student Time Simón 4 _ hour Phil 3 _ hour 12 4 1 27. OPEN ENDED Write three fractions that are not greater than _. 2 28. WHICH ONE DOESN’T BELONG? Identify the set of fractions that does not belong with the other three sets. Explain. 15 _1 , _5 , _ _2 , _1 , _1 7 _2 , _1 , _ 9 3 2 4 8 16 5 2 10 _3 , _1 , _2 4 2 12 150 29. CHALLENGE Identify a fraction that is greater than _. 500 30. E WRITE MATH Explain how to decide if 3 3 _ is greater than or less than _. 4 5 Test Practice 31. What fraction is equivalent to the fraction represented by point M on the number line? 32. Which set of fractions is ordered from greatest to least? (Lesson 2D) 3 6 2 F. _, _, _ (Lesson 2B) 5 15 10 M 1 0 8 1 4 3 8 1 2 5 8 7 8 1 A. _ 1 C. _ 3 B. _ 8 3 D. _ 4 2 3 6 G. _, _, _ 1 10 5 15 2 6 3 H. _, _, _ 10 15 5 2 6 3 2 I. _, _, _ 15 5 10 4 33. Toya h has 8 coins her piggy bank. One fourth of i iin h the coins is quarters. Three of the coins are dimes. The rest of the coins are pennies. How many pennies does Toya have? (Lesson 2C) Find an equivalent fraction for each fraction. (Lesson 2B) 1 34. _ 2 35. _ 3 36. _ 7 37. _ 1 38. _ 4 39. _ 2 10 3 8 To assess mastery of SPI 0406.2.6, see your Tennessee Assessment Book. 5 12 409 Multi-Part Lesson 2 Fractions PART A Main Idea I will write a fraction in simplest form. B C D E F Simplest Form 8 2 4 2 Among the equivalent fractions _, _, and _, the fraction _ 3 6 Vocabulary V simplest form greatest common factor Get ConnectED Fractions in Simplest Form 1 _ 2 SPI 0406.2.4 Find factors, common factors, multiples, and common multiples of two numbers. Also addresses GLE 0406.3.1. 3 12 is in simplest form because its numerator and denominator have no common factor other than 1. 2 _ 3 _ 3 4 3 _ 7 Fractions NOT in Simplest Form 5 _ 2 _ 4 8 4 _ 8 _ 6 8 _ 10 16 _ 24 12 To change a fraction into its simplest form, you can divide both the numerator and the denominator by the greatest common factor. A greatest common factor is the greatest of the common factors of two or more numbers. Simplest Form QUIZ There are 12 questions on a quiz. Esteban got 8 out of 12, or _8 , of the Name: 1. 12 questions correct. Two fractions equivalent to _8 are _2 and _4 . 8 Write _ in simplest form. 12 3 Step 1 3. 6 4. 5. 12 Find the common factors of 8 and 12. 7. 8. 2. 6. Factors of 8: 1, 2, 4, 8 Factors of 12: 1, 2, 3, 4, 6, 12 9. 10. 11. 12. Common factors: 1, 2 and 4 Step 2 Divide by the greatest common factor, 4. 8 ÷ 4 2 _ =_ 3 12 ÷ 4 The numbers 2 and 3 have no common factor other than 1. 8 2 _ So, in simplest form is _. 3 12 410 Decimals and Fractions To write a fraction in simplest form, you can also divide by common factors. Simplest Form ANIMALS Koala bears sleep up to 18 hours each day. What part of a day do koalas sleep? Write the fraction in simplest form. Step 1 Write a fraction. 18 _ 24 Step 2 Divide until the numerator and the denominator have no common factor other than 1. hours of sleep each day total hours in a day Divide by common factors. 18 ÷ 2 18 9 _ = _ =_ 24 24 ÷ 2 12 A common factor of 18 and 24 is 2. 9÷ 3 9 3 _ = _=_ 4 12 12 ÷ 3 A common factor of 9 and 12 is 3. 18 3 3 So, _ simplifies to _. Koalas sleep up to _ of a day. 24 4 4 Simplest Form One Way Divide the numerator and denominator by the greatest common factor. Another Way Divide the numerator and denominator by common factors until the only common factor is 1. Write each fraction in simplest form. form If it is in simplest form, form write simplest form. See Example 1 2 1. _ 4 6 2. _ 10 5 3. _ 6 18 4. _ 30 5. Daniela read for 24 minutes. What 6. E TALK MATH How do you 4 fraction of an hour did she read? Write know that _ is in simplest form? 5 as a fraction in simplest form. See Example 2 Lesson 2E Fractions 411 EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Write each fraction in simplest form. If it is in simplest form, write simplest form. See Example 1 2 7. _ 3 8. _ 7 9. _ 6 10. _ 4 11. _ 10 12. _ 18 13. _ 24 14. _ 32 15. _ 42 16. _ 10 12 27 15 20 9 40 16 56 42 Measurement What part of one day is each amount of time? Write as a fraction in simplest form. See Example 2 17. 9 hours 18. 16 hours 19. 20 hours Algebra Find the value of x to simplify each fraction. 15 x 20. _ = _ 45 16 4 21. _ = _ x 28 3 20 x 22. _ = _ 36 9 Write as a fraction in simplest form. 23. Six of the 16 marbles in a bag are yellow. What fraction of the marbles is yellow? 24. Adina read 12 out of 36 pages in a comic book. What fraction of the pages did she read? Measurement The table lists the length of some objects in a classroom. What part of a foot is each object? Write as a fraction in simplest form. See Example 2 25. pencil 26. crayon 27. scissors 28. pencil box 29. OPEN ENDED Write three fractions that are in simplest form. 30. WHICH ONE DOESN’T BELONG? Identify the fraction that does not belong with the other three. Explain your reasoning. 31. E _2 _6 _1 _ 11 3 15 2 12 WRITE MATH The simplest form of 6 2 _ is _. How can you 15 5 use multiplication to show that they name the same number? 412 Decimals and Fractions Test Practice 32. In the circle below, _ of the 8 sections are shaded. 4 33. Mr. Henshaw used some eggs from a full carton to make breakfast for his family. The eggs that are left are shown. Which of the following is equal 4 to _? (Lesson 2B) 8 1 A. _ 4 3 B. _ Identify the part of the eggs in the carton Mr. Henshaw used. 6 6 C. _ (Lesson 2E) 5 D. _ 4 2 G. _ 4 10 3 F. _ 12 H. _ 1 3 2 I. _ 3 34. Ashley has six coins. One third of the coins is quarters. She has 1 dime and the rest are nickels. What is the value of Ashley’s coins in decimal form? (Lesson 2C) Write the fraction for the part that is shaded. Then find an equivalent fraction. (Lesson 2B) 35. 36. 37. Determine whether the fractions are equivalent. Write yes or no. (Lesson 2A) 5 6 38. _ and _ 10 12 8 1 39. _ and _ 4 12 6 3 40. _ and _ 8 4 Lesson 2E Fractions 413 Multi-Part Lesson 2 Fractions PART A Main Idea I will write mixed numbers and improper fractions. Vocabulary V B C D F E Mixed Numbers A mixed number has a whole number part and a fraction part. An improper fraction has a numerator that is greater than or equal to its denominator. mixed number improper fraction Mixed Numbers 1_ Get ConnectED SPI 0406.2.2 Locate and place mixed numbers on the number line. SPI 0406.2.7 Convert improper fractions into mixed numbers and/or decimals. Also addresses GLE 0406.1.7. 2_ 3_ 3 4 1 2 Improper Fractions 3 _ 5 6 11 _ FOOD Nyoko is selling pies at a bake sale. Each pie has 5 slices. There are 7 slices left. What fraction of the pies is left? Mixed Number Count the wholes and the parts. 1 5 Another Way: 1 5 1 5 1 5 1 5 1 5 1 5 _5 + _2 = 1_2 5 5 5 1 5 1 5 1 5 part 2 7 So, 1_, or _, of the pies are left. 5 5 1 5 1 5 _7 5 whole Improper Fraction Count the parts. 1 5 1 5 Decimals and Fractions 6 Mixed Numbers and Improper Fractions One Way: 414 23 _ 4 2 You can change from a mixed number to an improper fraction. You can also change from an improper fraction to a mixed number. Mixed Number to Improper Fraction _3 as an improper fraction. Write 1 W 8 3 3 1_ = 1 + _ Write the mixed number as the sum 8 of a whole and part. 8 3 = _ + _ Write the whole number as a fraction. 8 8 8 + 3 = _ Add. 8 11 = _ 8 8 Write W 11 _ as a mixed number. 8 Divide the numerator by the denominator. s The fraction bar stand 11 _ for divided by. So, 8 1 R3 8 11 -8 numerator −− 3 whole number means 11 divided by 8. denominator 3 11 So, _ = 1_ . 8 8 You can show improper fractions and mixed numbers on a number line. Use a Number Line Identify point A as a mixed number and improper fraction. A 4 5 6 Each interval on the number line is one third. So, point A 1 is 5 _. 3 A 4 5 51 6 3 3 3 3 3 3 1 1 5_ = _ + _ + _ + _ + _ + _ 3 3 3 3 3 3 3 3+3+3+3+3+1 16 = __ = _ 3 16 1 So, point A is 5 _, or _ . 3 3 3 Lesson 2F Fractions 415 Write a mixed number and an improper fraction for each model model. See Example 1 1. 2. 3. Write each as an improper fraction or a mixed number. Use models if needed. See Examples 2 and 3 4. 1_ 5. 2_ 9 6. _ 3 4 2 5 13 7. _ 4 3 Identify each point as a mixed number and an improper fraction. See Example 4 B 8. 7 G 9. 8 4 9 10. Andrew’s family ate 1 _ pizzas and 3 8 4 Sheri’s family ate 1_ pizzas. Who ate 16 11. 5 6 E TALK MATH Explain how to compare 3 17 2 _ and _. 5 5 more pizzas? EXTRA % )# E # T4 IC !C 2A PR 0 Begins on page EP2. Write a mixed number and an improper fraction for each model. See Example 1 12. 13. 14. Write each as an improper fraction or a mixed number. Use models if needed. See Examples 2 and 3 15. 1_ 16. 2_ 17. 6_ 7 8 18. 8_ 7 19. _ 17 20. _ 45 21. _ 50 22. _ 3 4 3 416 7 10 5 Decimals and Fractions 8 5 8 6 Identify each point as a mixed number and an improper fraction. See Example 4 23. X W 1 2 24. 3 M 4 N 5 Travel A diagram of a horseback riding tour is shown. There are resting stops along the trail. 25. Joaquin and his family started at the stables on the left. They are at the covered bridge. How many miles of the trail have they traveled? 26. Joaquin reached the end of the trail in 2 hours and 15 minutes. Write the amount of time he spent on the trail as an improper fraction. Use the information to solve the problem. Flying Flying Feat Feat Remember, the class is having a paper airplane contest. So far the distances are: Ethan—64_1 feet, Julian—63_1 feet, Olivia—74_3 feet, and Teresa—52_1 feet. My airplane distance is 72_1 feet. So, who won the contest? 27. Whose paper airplane went the farthest? Explain. 28. OPEN ENDED Name an improper fraction that can be written as a whole number. 29. E WRITE MATH Compare fractions, mixed numbers, and improper fractions. Lesson 2F Fractions 417 Test Practice 30. Lionel used 2 _ cups of pancake mix. 2 Which improper fraction shows the number of cups of pancake mix he used? (Lesson 2F) 1 2 A. _ 4 C. _ 3 B. _ 2 5 D. _ 2 2 2 4 1 F. 3_ H. 3_ G. 3_ I. 3_ 2 5 1 5 2 6 33. Caroline has a bag of marbles. In simplest form, what fraction of the marbles are blue? (Lesson 2E) 32. The table shows the number of minutes Grant read each day. Grant’s Reading Log Minutes Monday 30 Wednesday 55 Friday 45 What fraction of an hour did he read on Friday? (Lesson 2E) 1 3 C. _ A. _ 5 4 1 B. _ 2 3 2 2 Day 31. What mixed number does point A represent? (Lesson 2F) A 3 D. _ 3 F. _ H. _ G. _ 4 I. _ 4 6 10 2 5 5 4 Write each fraction in simplest form. If it is in simplest form, write simplest form. (Lesson 2E) 4 34. _ 8 35. _ 6 5 36. _ 10 8 Compare. Use >, <, or =. (Lesson 2D) 1 1 37. _ _ 8 6 4 1 38. _ _ 12 3 5 5 39. _ _ 6 40. Zaria counted ten insects on her deck. Half of the insects were ants. Three were ladybugs, and the rest were crickets. How many insects were crickets? (Lesson 2C) 418 To assess mastery of SPI 0406.2.2 and partial mastery of SPI 0406.2.7, see your Tennessee Assessment Book. 10 Mid-Chapter Check Write each decimal. (Lesson 1B) 1. three-tenths 3. one out of ten 2. eight-tenths 4. four out of ten 5. MULTIPLE CHOICE There were ten peaches in a bag. Some were eaten. The peaches below were not eaten. What decimal shows the part of the peaches that was eaten? (Lesson 1B) A. 0.4 C. 0.9 B. 0.6 D. 0.10 6. Write a decimal for the part of a dollar shown. (Lesson 1C) Find an equivalent fraction for each fraction. (Lesson 2B) 1 14. _ 3 15. _ 5 16. _ 4 17. _ 6 9 5 10 18. Stewart has a collection of 12 footballs. Nine footballs have been signed by professional football players. The others have not. What part of the footballs has not been signed? Write an equivalent fraction. (Lesson 2C) Write each fraction in simplest form. (Lesson 2E) 8 _ 3 19. _ 20. 6 21. _ 12 22. _ 6 30 10 20 23. Write a mixed number and an improper fraction for the model. (Lesson 2F) 7. Mark has six apples. He cut each apple into 10 slices to share with his family. There are 13 slices left after his family eats. Write a decimal that describes the leftover apples. (Lesson 1D) Compare. Use >, <, or =. (Lesson 1E) 8. 0.49 0.7 10. 82.6 82.60 9. 1 0.90 24. MULTIPLE CHOICE Which set of fractions is in order from greatest to least? (Lesson 2D) 3 6 2 F. _, _, _ 11. 1.06 1.07 5 15 10 2 3 6 G. _, _, _ 10 5 15 Order from least to greatest. (Lesson 1E) 12. 0.98, 0.79, 0.89, 1.87 13. 5.3, 5.23, 4.62, 5.20 25. E 2 6 3 H. _, _, _ I. 10 15 5 6 _ 3 2 _ , ,_ 15 5 10 3 WRITE MATH Explain why ___ 10 30 and ____ are equivalent. (Lesson 2B) 100 Mid-Chapter Check 419 Multi-Part Lesson 3 MP-Title -TitlFractions e Relate and Decimals A PART B C D E Fractions and Decimals Main Idea I will explore fractions and decimals. A fraction shows part of a whole. A decimal also shows part of a whole. A decimal is a number that uses place value, numbers, and a decimal point to show part of a whole. Get ConnectED GLE 0406.2.4 Understand and use the connections between fractions and decimals. W Write a fraction and a decimal ffor the shaded part. Step 1 Find the shaded parts and the total number of parts. There are 34 shaded parts out of a total of 100 parts. Step 2 Write a fraction. 34 _ 100 Step 3 Write a decimal. Write thirty-four hundredths as a decimal. 0.34 hundredths place 34 So, the shaded part of the model is _, or 0.34. 100 and Apply It Write a fraction and a decimal for each model. 1. 4. 420 2. E 3. WRITE MATH Explain how to find the decimal equivalent of Decimals and Fractions 2 _ . 100 Multi-Part Lesson 3 Relate Fractions and Decimals PART A Main Idea I will identify, read, and write tenths, hundredths, and thousandths as decimals and as fractions. B C D E Fractions and Decimals A decimal is a number that uses place value and a decimal point to show part of a whole. Get ConnectED MONEY It costs 85 cents for a child to ride a light rail system. Write 85 cents as a fraction and as a decimal. The amount 85 cents means 85 pennies out of 1 dollar. Read Write eighty-five hundredths 85 _ or 0.85 100 Read Write Hundredths Place Value Tenths Draw a hundreds model. Shade 85 out of 100 parts to show 85 cents. Another Way: Ones Use a Model Tens One Way: Hundreds GLE 0406.2.4 Understand and use the connections between fractions and decimals. Also addresses GLE 0406.1.6. 0 8 5 eighty-five hundredths 85 _ or 0.85 100 85 So, 85 cents is _ as a fraction and 0.85 as a decimal. 100 Lesson 3B Relate Fractions and Decimals 421 Some fractions can be written as tenths, hundredths, or thousandths. Write Fractions as Decimals Write W _5 as two different decimals. 10 One Way: Another Way: Write Tenths Write Hundredths 0.5 0.50 The decimals 0.5 and 0.50 are equivalent decimals. Write W Read Write 23 _ as a decimal. 1,000 twenty-three thousandths 0.023 23 So, _ can be written as 0.023. 1,000 Write a fraction and a decimal for each shaded part part. SSee Example E l 1 1. 2. 3. Write as a fraction and as a decimal. See Examples 1–3 4. one-tenth 7. E 5. twenty-five hundredths 6. seven-thousandths TALK MATH Shade all of the boxes along the outer edge of a hundredths grid. Write a fraction and decimal for the shaded part. Why is it not 0.40? 422 Decimals and Fractions EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Write a fraction and a decimal for each shaded part. See Example 1 8. 9. 10. 11. 12. 13. Write as a fraction and as a decimal. See Examples 1–3 14. sixty-two hundredths 15. two-tenths 16. thirty-five hundredths 17. eight-tenths 18. fourteen-thousandths 19. six-thousandths Write each fraction as a decimal. 22 20. _ 2 21. _ 100 50 23. _ 100 100 375 24. _ 1,000 26. On Monday, it snowed _ of 10 an inch. 6 28. Each state has a representation 2 of _ in the United States Senate. 100 2 22. _ 10 80 25. _ 1,000 3 27. A car traveled _ of a mile in 18 10 seconds. 29. Wesley learned that _ of the 10 students in his class are left handed. 2 2 30. OPEN ENDED Write a fraction whose decimal value is between _ 10 25 and _. Write the fraction and its decimal equivalent. 100 31. CHALLENGE Decide whether the following sentence is true or 6 false. Explain. The fraction _ equals 0.0006. 10,000 32. E WRITE MATH Write a summary statement about decimals equivalent to fractions that have denominators of 10 and 100. Lesson 3B Relate Fractions and Decimals 423 in Music Decimal Musical notes are a universal language. Musical notes are based on fractions. The most common musical notes include whole, half, quarter, eighth, and sixteenth notes. These values represent the duration of the notes. The durations of the notes are not o o N te-ati n specific; they are relative to the other notes. For example, a one-eighth note is twice as long as a one-sixteenth note, a one-fourth note is twice as long as a one-eighth note, and so on. Beethoven was the first musician to use the one hundred twenty-eighth note. 424 Decimals and Fractions Note Notation Fractional Equivalent Whole 1 _ Half 1 _ Quarter 1 _ 1 2 4 Use the table above to solve each problem. m. Write the value of each musical note as a decimal. Refer to Exercises 1–3. Draw a number line that shows these values. Write the value of each group of musical notes as a mixed number. Draw three musical notes that represent a value of 2.5. Draw four musical notes that 1 represent a value of 2 _ . 4 Problem Solving in Music 425 Multi-Part Lesson 3 Relate Fractions and Decimals PART A B C D E Problem-Solving Investigation Main Idea I will choose the best strategy to solve a problem. Clarissa visited a fair on Saturday and played 0.20 of the games. She visited the fair again Sunday. By the end of the day she still had not played 0.62 of the games. What part of the 100 fair games did she play on Sunday? Understand What facts do you know? • There are 100 games at the fair. • She played 0.20 of the games on Saturday. • She did not play 0.62 of the games. What do you need to find? • The part of the 100 fair games she played Sunday. Plan Work backward to find the part of the games she played Sunday. Solve 0.62 = 62 games out of 100 not played 0910 100 - 62 −−−− 38 total games games not played 38 out of 100, total games played or 0.38 38 - 20 −−−− 18 total games played games played Saturday 18 out of 100, games played Sunday or 0.18 So, she played 18 out of 100, or 0.18, of the games Sunday. Check Add the total number of games she played to the number of games she did not play. 62 + 38 = 100 So, the answer is correct. GLE 0406.1.2 Apply and adapt a variety of appropriate strategies to problem solving, including estimation, and reasonableness of the solution. GLE 0406.2.6 Solve problems involving whole numbers, fractions, and/or decimals using all four arithmetic operations. 426 Decimals and Fractions EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. • Make a model. • Make a table. • Choose an operation. 6. Algebra The table shows the number of shapes after a pattern repeats itself five times. How many of each shape are in the original pattern? Use any strategy to solve each problem. Pattern 1. There are 18 students in Mr. Case’s class. Twelve of the students play an instrument. What fraction of the students play an instrument? Shape Number Circles Squares Hearts 15 5 10 7. Mr. Lawrence used 100 tiles when he put a new floor in the kitchen. Thirty-four tiles are blue and 16 tiles are gray. Write the total amount of blue and gray tiles as a decimal and a fraction. 2. Mrs. Keys has 36 pens. Yesterday she had half that amount plus 2. How many pens did she have? 3. There are three lines. The first line is 3 times as long as the second. The second line is 4 inches longer than the third. The third line is 2 inches long. How long is the first line? 4. The table below shows Adelais’ schedule. She finished at 5:00 P.M. What time did she start her lunch? 8. Cathy baked 36 muffins. She gave half the muffins to her neighbor and ate the muffins shown below. She brought the rest to school. What fraction of the muffins did Cathy bring to school? Write in simplest form. Adelais’ Schedule Activity Time Lunch 1 hour Scrapbooking 3 hours 9. Giselle played with some friends on Monday. She played with 2 times as many friends on Wednesday. This was 4 more than on Friday. On Friday there were 4. How many did she play with on Monday? 5. Dirk ran eight-tenths of a mile at track 80 practice. Leslie ran _ of a mile. Who 100 ran farther? Write each distance as a decimal. 10. E WRITE MATH Look back at Exercise 9. Explain which strategy you used to solve the problem. Lesson 3C Relate Fractions and Decimals 427 Multi-Part Lesson 3 Relate Fractions and Decimals PART A Main Idea I will explore fraction and decimal equivalents. B C D E Model Fraction and Decimal Equivalents You can use a number line to find fraction and decimal equivalents. Get ConnectED GLE 0406.2.4 Understand and use the connections between fractions and decimals. SPI 0406.2.5 Generate equivalent forms of common fractions and decimals and use them to compare size. _1 are equivalent. Determine whether 0.2 and D Step 1 5 Model 0.2. Use a number line to model 0.2. 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Step 2 Model _1 . 5 1 Use a number line to model _ . 5 Step 3 0 5 1 5 2 5 3 5 4 5 5 5 0 0.2 0.4 0.6 0.8 1 Compare. 1 Compare the locations of 0.2 and _ on the 5 number lines. 0 10 1 0.2 and 5 are located in the same position on the number lines. 1 10 2 10 3 10 4 10 7 10 8 10 9 10 10 10 0 5 1 5 2 5 3 5 4 5 5 5 0 0.2 0.4 0.6 0.8 1 5 Decimals and Fractions 6 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 So, 0.2 and _ are equivalent. 428 4 5 10 Find fraction and decimal equivalents. F Write a fraction and a decimal to describe the shaded part of the model. Step 1 Identify the fraction. Determine which fraction the model represents. One out of four equal parts of the model is shaded. 1 So, the model represents _. 4 Step 2 Find a decimal equivalent. Divide the model into 100 equal parts. Then count the shaded squares. 25 25 out of 100, or _, or 0.25 100 of the squares are shaded. 1 So, 0.25 is a decimal equivalent to _ . 4 About It 3 1. Do 0.6 and _ represent equivalent amounts? Explain. 5 3 2. Is the fraction _ equivalent to 0.7? Explain. 4 and Apply It Write a decimal equivalent for each fraction. 1 3. _ 2 6. E 4 4. _ 5 3 5. _ 4 WRITE MATH Explain how to find an equivalent decimal for _2 . 4 Lesson 3D Relate Fractions and Decimals 429 Multi-Part Lesson 3 PART Relate Fractions and Decimals A Main Idea I will find fraction and decimal equivalents. Get ConnectED B C E D Fraction and Decimal Equivalents When a fraction and a decimal name the same amount, they are fraction and decimal equivalents. GLE 0406.2.4 Understand and use the connections between fractions and decimals. SPI 0406.2.5 Generate equivalent forms of common fractions and decimals and use them to compare size. TRAVEL Austin’s family is taking a trip. The odometer (mileage tracker) shows they have driven 0.5 mile. Austin wants to find this in a fraction. Use a model to find an equivalent fraction. Use tenths and hundredths grids to model that 0.5 and 0.5 = _5 = _1 2 0.50 = 2 10 _1 name the same amount. 50 1 _ =_ 2 100 The number lines also show that they name the same amount. 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 2 1 2 2 2 0 0.5 1.0 So, 0.5 and 430 Decimals and Fractions _1 are equivalent. 2 To find a decimal that is equivalent to a fraction, it helps to write the fraction with a denominator of 10 or 100. Find Fraction and Decimal Equivalents W Write a fraction and a decimal to describe the shaded part of the model. 3×2 25 75 _ =_ 4 × 25 100 75 _ = 0.75 100 THINK What number can you multiply the denominator by to get 100? 75 Write _ as a decimal. 100 3 So, _ and 0.75 describe the shaded part of the model. 4 Here are some common fraction and decimal equivalents. Fraction-Decimal Equivalents 1 _ = 0.5 1 _ = 0.25 2 _ = 0.5 3 _ = 0.75 1 _ = 0.2 2 _ = 0.4 3 _ = 0.6 4 _ = 0.8 2 5 4 5 4 4 5 5 decimal. SSee EExample Use a model to find an equivalent fraction or decimal l 1 1. 0.6 2. 0.06 2 3. _ 4 4 4. _ 5 Write a fraction and a decimal to describe the shaded part of each model. See Example 2 5. 6. 9. Lupe got 20 out of 25 questions correct on a quiz. Write her score as a decimal and a fraction. 7. 10. 8. E TALK MATH What do you notice 3 6 12 about _ , _ , and _ ? 4 8 16 Lesson 3E Relate Fractions and Decimals 431 EXTRA % )# E # T4 IC !C 2A 0R P Begins on page EP2. Use a model to find an equivalent fraction or decimal. See Example 1 11. 0.78 12. 0.4 13. 0.6 14. 0.35 1 15. _ 4 16. _ 7 17. _ 1 18. _ 4 5 25 10 Write a fraction and a decimal to describe the shaded part of each model. See Example 2 19. 20. 21. 22. 23. 24. 25. 26. Write each amount as a fraction and a decimal. 27. Measurement Adelina swam 3 out of 4 laps. 28. Vince read 6 out of 10 pages in a chapter of a book. 29. Jun ate 8 out of her 10 orange slices. 30. Cathy has completed 18 out of 20 math problems. 31. Maya has painted 1 out of 4 walls of her bedroom. 32. Jack has opened 3 out of 5 of his birthday presents. 33. OPEN ENDED Create a model and shade in a fraction of it. Write two fractions and a decimal to describe the shaded area of the model. 34. CHALLENGE Carra collects stuffed frogs. She has 25 frogs, and 2 _ of them are multicolored. The rest are green. How many green 25 frogs are in her collection? Explain how you found your answer. 35. E WRITE MATH Demetri is completing 0. = Explain how he can find the correct answer. 432 5 _ . 50 To assess mastery of SPI 0406.2.5, see your Tennessee Assessment Book. Fraction and Decimal Game You will need: 10 index cards Compare Decimals to Fractions Get Ready! Players: 2 Get Set! On each index card, write a statement using >, <, or =. Write 5 true statements and 5 false statements. A few examples are shown at the right. 0.25 < _31 10 0.5 > _ 20 0.75 = _4 75 0.8 < _ 3 100 GO! Shuffle the cards. Spread out the cards facedown on a desk. Player 1 turns over an index card and must say whether the statement is true or false. Player 1 keeps the card if the answer is correct and draws again. If Player 1 is wrong, the index card is put back. Player 2 takes a turn. The player who collects more cards wins. Game Time Fraction and Decimal Game 433 Chapter Study Guide and Review Be sure the following Key Concepts are noted in your Foldable. Key Vocabulary decimal equivalent fractions greatest common factor Decim als Frac t ions mixed number Equ F ival and ractio ent Dec ns ima ls simplest form Vocabulary Check Complete each sentence with the correct vocabulary word. Key Concepts Decimals (Lesson 1) 1. The • Tenths , hundredths , and thousandths are used to describe decimals as part of the base-ten system. Fractions (Lesson 2) • Equivalent fractions represent the same amount. 1 _ 2 _ 4 _ 4 2 2 2 14 2.5 2 12 2.75 3 2 34 3 • When a fraction and decimal name the same amount, they are equivalents. 434 Decimals and Fractions 2 2. The fraction _ is written in 3 ? . ? has a whole 3. A(n) number part and a fraction part. ? is 10 • Mixed numbers can be written as decimals. 2.25 of 8 and 12 is 4. 4. An example of a(n) 2 5_. 8 Fractions and Decimals (Lesson 3) 2 ? 5. Fractions that represent the ? same amount are . ? is a number that 6. A uses place value, a number, and a decimal point to show part of a whole. Multi-Part Lesson Review Lesson 1 Tenths Decimals (Lessons 1A and 1B) EXAMPLE 1 Model and write each decimal. Sandra knocked down seven out of ten pins with her first bowling ball. What part of the set of pins is still standing? 7. one out of ten 8. five out of ten 9. nine out of ten 10. Caleb ate six out of ten pretzels. Write a decimal to show what part of the pretzels Caleb did not eat. Hundredths If seven out of ten pins were knocked down, then three pins are still standing. The amount of pins still standing is three out of ten, three-tenths, or 0.3. (Lesson 1C) Write a decimal for each part of a dollar shown. 11. EXAMPLE 2 Write a decimal for the part of a dollar shown. 12. Each cent is one hundredth, or 0.01, of a dollar. So, thirty-seven cents is 0.37 of a dollar. (Lesson 1D) Hundredths 15. On average, a United States citizen eats eleven and eighty-eight hundredths pounds of breakfast cereal each year. Write this amount in standard and expanded form. Write fourteen and thirty-seven hundredths in standard and expanded form. Write each digit in the decimal in a place-value chart. Tenths 14. eight and ninety-four hundredths EXAMPLE 3 Ones Write each decimal in standard and expanded form. 13. two and eighteen hundredths Tens Decimals Greater Than One 1 4 3 7 Standard form: 14.37 Expanded form: 10 + 4 + 0.3 + 0.07 Chapter Study Guide and Review 435 Chapter Study Guide and Review Compare and Order Decimals (Lesson 1E) 1 sandwich and said, “Here is your _ 2 of the sandwich.” Her brother said, 2 “Actually, you ate _ of it.” Who is 4 correct? Explain. Lesson 2 Compare 5.34 and 5.32. 4>2 5.34 > 5.32 5 5 3 3 4 2 So, Stephanie has been jogging longer. Fractions Equivalent Fractions (Lessons 2A and 2B) Find an equivalent fraction for each fraction. EXAMPLE 5 1 20. _ 1 21. _ 1 22. _ 4×2 8 _ =_ 6×2 12 6 23. _ 7 24. _ 9 25. _ 5 8 3 14 4 12 Find a fraction equivalent to Solve. Use the make a model strategy. 1 26. Jeff had 28 grapes. He ate _ of them 2 for lunch. Then he ate 10 more as a snack. How many are left? 27. Marisa has a marble collection. One-fourth of her 16 marbles is blue. She has 5 red marbles. The rest of the marbles are green. How many are green? Decimals and Fractions _4 . 6 Multiply the numerator and the denominator by the same number, 2. 8 4 _ So, is equivalent to _. 6 12 Problem-Solving Strategy: Make a Model 436 Hundredths 19. Della gave her brother part of a Stephanie has been jogging for 5.34 minutes. Todd has been jogging for 5.32 minutes. Who has been jogging longer? Tenths 16. 4.35 3.45 17. 6.40 6.40 18. 2.27 2.72 Ones EXAMPLE 4 Compare. Use >, <, or =. (Lesson 2C) EXAMPLE 6 _1 Marcela has 24 crayons. Of them, is 3 blue. Four are yellow, and the rest are green. How many crayons are green? Make a model. There are 12 parts left. So, 12 of the crayons are green. Compare and Order Fractions (Lesson 2D) EXAMPLE 7 Compare. Use >, <, or =. 4 8 28. _ _ 5 6 5 29. _ _ 6 10 Dakota has a red and a blue pencil. The 1 red pencil is of a foot long. The blue 3 2 pencil is of a foot long. Which pencil 8 is longer? Find an equivalent fraction. 6 2 3 4 30. _, _, _ 1 3 7 31. _, _, _ 3 7 35 _ _ Order from least to greatest. 4 16 8 1 4 4 _ ×_=_ 3 32. Measurement Patrick took _ of 4 3 an hour to finish a test. Jose took _ of 8 an hour to finish. Who took more time to finish the test? Simplest Form 4 2 3 4 _ > _ 8 8 8 So, the red pencil is longer than the blue pencil. (Lesson 2E) Write each fraction in simplest form. If it is in simplest form, write simplest form. 4 33. _ 2 34. _ 6 35. _ 3 36. _ 10 13 3 18 EXAMPLE 8 Write 20 Factors of 15: 1, 3, 5, 15 Factors of 20: 1, 2, 4, 5, 10, 20 The greatest common factor is 5. 15 5 3 _ ÷_ =_ 20 Mixed Numbers 1 15 _ in simplest form. 5 4 (Lesson 2F) Write a mixed number and an improper fraction for each model. EXAMPLE 9 37. A fourth grade class had a pizza party. The amount of pizza eaten can be 1 represented as 3_ . Write the amount 5 of pizza eaten as an improper fraction. 38. 5+5+5+1 5 5 5 1 1 3_ = _ + _ + _ + _ = __ 5 5 16 =_ 5 5 5 5 5 16 1 So, 3 _ = _. 5 5 Chapter Study Guide and Review 437 Chapter Study Guide and Review LLesson esson 3 Relate Fractions and Decimals Fractions and Decimals (Lessons 3A and 3B) 39. Write a fraction and a decimal for the shaded part. EXAMPLE 10 Write eight tenths as two different decimals. Write tenths. Write hundredths. Write as a fraction and as a decimal. 40. three-tenths 41. twenty-two hundredths 0.8 0.80 Eight tenths can be written as 0.8. Problem-Solving Investigation: Choose a Strategy (Lesson 3C) Use any strategy to solve each problem. EXAMPLE 11 42. Jonas earned $5.25. Ian earned $5.50. Who earned more money? A one-year-old puppy has three new toys. A day later, the puppy has one-third of the toys. How many toys does the puppy have left? 43. Zach has $30. Tickets to the school baseball game cost $7. How much money will Zach have left if he buys 3 tickets? Fraction and Decimal Equivalents Write a fraction and a decimal to describe the shaded part of each model. 44. 45. Find _ of 3. You do not need to know 3 the age of the puppy. So, the puppy has one toy left. 1 (Lessons 3D and 3E) EXAMPLE 12 Write a fraction and a decimal to describe the shaded part of each model. Thirty-two squares are shaded. So, 32 that is _, or 0.32. 100 438 Decimals and Fractions Practice Chapter Test Tell whether each statement is true or false. 1 1. _ and 0.5 are equivalent. 5 2. To find an equivalent fraction, multiply or divide the numerator and denominator by the same number. Write as a fraction and as a decimal. 3. one-tenth 4. nine-tenths Compare. Use > , < , or = . 9. 4.75 4.77 10. 3.21 3.20 Write each as a mixed number or an improper fraction. 11. 2_ 27 12. _ 3 4 5 13. There are 12 fish in an aquarium. One-half of the fish is goldfish. Four of the fish are tetras. The rest of the fish are rainbow fish. How many of the fish are rainbow fish? Identify each point as a mixed number. 5. eighteenhundredths 6. threehundredths A 14. 5 7. Madison emptied her pockets. Her coins are shown. What decimal represents the part of a dollar shown? 6 15. B 2 3 16. Abby read _ of a book on Saturday. 10 Then she read 0.4 of the book on Sunday. What fraction of the book does Abby still have to read? 3 8. MULTIPLE CHOICE Which number is NOT equivalent to the shaded area of the circle? 1 A. _ 2 2 B. _ 4 C. 0.5 D. 0.4 17. MULTIPLE CHOICE Which set of numbers is in order from least to greatest? 18. F. 0.6, 0.76, 0.67 H. 0.6, 0.67, 0.76 G. 0.76, 0.67, 0.6 I. E WRITE MATH 0.67, 0.6, 0.76 2 Explain how _ 6 and _ are equivalent fractions. 7 21 Practice Chapter Test 439 Test Practice On the number line below, what mixed number does point K represent? K 7 8 A. 7_ Count the intervals between whole numbers on a number line to find how the number line is divided. 4 C. 7_ 3 10 4 B. 7_ 6 10 4 D. 7_ 5 Read the Question You need to find which number point K represents. Solve the Question Look at the number line. The 9 marks between the 1 7 and 8 let you know that each line is _. Fill in 10 the numbers up to point K. K 7 7 1 7 2 7 3 7 4 7.5 8 10 10 10 10 4 So, point K represents 7_ on the number line. 10 The answer is C. Read each question. Then fill in the correct answer on the answer sheet provided by your teacher or on a separate sheet of paper. 1. On the number line below, what number does point A represent in decimal form? A 2 440 1 22 3 A. 2.3 C. 2.75 B. 2.5 D. 2.8 Decimals and Fractions 2. Which symbol makes the following sentence true? 13.08 1.308 F. > H. = G. < I. - 4 3. In the rectangle below, _ of the 8 sections are shaded. 6. GRIDDED RESPONSE The function table shows some input and output values. Input (x) 4 Which of the following is equal to _ ? A. _ B. _ 1 4 4. 1 2 C. _ D. _ 1 8 8 4 4 GRIDDED RESPONSE The elephants below each weigh 16,500 pounds. How many pounds do they weigh altogether? 1 1 2 4 3 7 4 10 5 What is the missing value? 7. The table shows how long Tara read each night during a week. What fraction of an hour did she read on Wednesday? Day 5. Which order shows the distances run from greatest to least? Track Practice Runner Miles Darin 1.24 Kirk 1.5 Damon 1.31 Output (y) Minutes Read Monday 17 Tuesday 24 Wednesday 36 Thursday 30 Friday 32 A. _ 3 C. _ 1 2 2 B. _ 3 5 36 D. _ 100 4 8. Trina grew _ of an inch in a year. F. Kirk, Damon, Darin 5 G. Kirk, Darin, Damon 4 Which decimal is equivalent to _ ? H. Damon, Darin, Kirk F. 0.7 H. 0.8 I. Damon, Kirk, Darin G. 0.75 I. 0.85 5 NEED EXTRA HELP? If You Missed Question... Go to Chapter-Lesson... For help with... 1 2 3 4 5 6 7 8 8-3E 8-1E 8-2B 5-4A 8-1E 3-4A 8-2E 8-3E GLE 2.4 SPI 2.5 SPI 2.5 SPI 2.11 SPI 2.1 GLE 3.2 SPI 2.4 SPI 2.5 Test Practice 441