WHOLE BRAIN LEARNING SYSTEM OUTCOME-BASED EDUCATION GRADE MATHEMATICS LEARNING MODULE QUARTER WEEK 6 2 1 1 MODULE IN MATHEMATICS 6 QUARTER 2 WEEK 1 Expressing One Value as a Fraction of Another Ratio and Proportion Development Team Writers: Nelia T. Obrero Gemma B. Jose Editors/Reviewers: Josephine Gloria S. Tudlong Ma. Mercedes G. Colobong Donna Hazel G. Palafox Illustrators: Jeshimon C. Patoc Ronie P. Fiesta Layout Artists: Nelia T. Obrero Gemma B. Jose Management Team: Vilma D. Eda Arnel S. Bandiola Lourdes B. Arucan Juanito V. Labao Marlyn S. Ventura 2 What I Need to Know This module was designed to help you understand the concept of ratio and proportion. Through this concept, we can apply it accurately in our day to day lives like in budgeting, cooking, baking and in business. As you go through the different activities, you will learn the importance of ratio and proportion in real-life situations. MELC: 1. Visualizes the ratio of two given numbers. 2. Expresses one value as a fraction of another given their ratio and vice versa. 3. Defines and illustrates the meaning of ratio and proportion using concrete or pictorial models. OBJECTIVES: At the end of this module, you should be able to: 1.visualize the ratio of two given numbers; 2. express one value as a fraction of another given their ratio and vice versa; and 3. define and illustrate the meaning of ratio and proportion using concrete or pictorial models. 3 What I Know Directions: Read and analyze each item carefully. Write the letter of the correct answer in a separate sheet of paper. 1. Which ratio is different from the others? A. 3 to 7 B. 7:3 C. 3:7 3 D. 7 2. Express 4:12 into fraction form. A. 12 4 4 B. 4 = 12 C. 12 D. 12 over 4 B. 1:5 C. 3 : 6 = 4 : 8 D. 7 over 10 3. Which is a proportion? 2 A. 3 4. There are 4 boys and 3 girls in a family. What is the ratio of the boys to girls? A. 3:4 B. 4:3 C. 7:3 D. 3:7 5. Which of the following is the ratio of leaves to flowers? A. 3 to 4 B. 4 to 5 C. 4 to 3 D. 5 to 4 6. What is the ratio of books to pupils if the teacher distributed 45 books to 45 ? pupils? A. 1:45 B. 1:12 C. 45:45 D. 45:1 7. What is the lowest term of the ratio 20 to 25? A. 4:5 B. 8:10 C. 10:15 D. 10:12 For numbers 8-10, refer to the figure below: 8. What is the ratio of triangles to squares? A. 2:3 B. 3:4 C. 3:3 D. 3:2 9. What is the ratio of circles to all of the shapes? A. 3:12 B. 1:3 C. 3:8 D. 1:1 10. What is the ratio of stars to all of the shapes? A. 4:3 B. 4:2 C. 4:12 D. 3:2 4 Lesson 1 Expressing One Value as a Fraction of Another Given Their Ratio and Vice Versa What’s In In a sheet of paper, do the following activities: A. Solve for N 2 1. 3 ÷ 6 = N 2. 2 3. 1 1 2 ÷8=N 3 ÷6=N 3 4. 6 ÷ 5 = N B. Give the fractional part of the shaded portion. 1. 4. 2. 3. 5. Lesson Guide in Elementary Mathematics Grade 6, Ateneo de Manila University, Book Media Press, Inc.,2010, p.29 5 What’s New Let us read and analyze the problem. In Ms. Trinidad’s Grade 6 Online Class in Mathematics, there are 17 girls and 15 boys. Compare the number of girls to the number of boys and vice versa. Study the illustrations: Guide Questions: What does the problem ask for? ____________________________________ How will you compare the number of girls to the number of boys? __________ How will you compare the number of boys to the number of girls? _________ What is It To compare, let us use the concept of ratio. Ratio is defined as a comparison of two quantities. Given that there are 17 girls and 15 boys, we can say that 17 to 15 in comparing girls to boys. Other ways to express such comparison is by writing them using a colon, 𝟏𝟕 17:15 or writing them in fraction form, 𝟏𝟓 . 17 is the 1st term which refers to the girls, 15 is the 2nd term which refers to the boys. 6 Using colon 17:15 Using fraction form 17 15 In words 17 to 15 In comparing the number of boys to the number of girls, it can be expressed as: 𝟏𝟓 15 to 17, 15:17, or 𝟏𝟕 , 15 is the 1st term which refers to the boys, 17 is the 2nd term which refers to the girls. Using colon 15:17 Using fraction form 15 17 In words 15 to 17 Ratio is the spoken language of arithmetic. It is a way of comparing two or more quantities having the same units - the quantities may be separate entities or they may be different parts of a whole. We can write the ratio of a and b in three ways: Using colon a:b Using fraction form 𝑎 𝑏 In words a to b Let us have more examples on writing ratios: 1. What is the ratio of oblongs to triangles? Write the ratio in three forms. Using colon 10 : 17 Using fraction form 10 17 In words 10 to 17 7 2. What is the ratio of cupcakes to ice creams? Write the ratio in three forms. Using colon 8 : 14 Using fraction form 8 14 In words 8 to 14 Ratio must be expressed in simplest form, which means that the terms are relatively prime to each other. If there are 20 boys and 16 girls in a class, then, the ratio of the boys to the girls is 20 is to 16 and the ratio of the girls to the boys is 16 is to 20. In a ratio, 20 to 16, the first term is 20 and the second term is 16. It may also be written as 20:16 or 20 . Even if the ratio is in fractional form, we say twenty to 16 sixteen. Now let us reduce the ratio in simplest form. Step 1: Find the Greatest Common Factor (GCF) of 20 and 16 using prime factorization. 20 10 5 16 2 8 2 4 2 2 2 2 20 = 5 X 2 X 2 16 = 2X2X2X2 GCF = 2 x 2 =4 Step 2: Divide the first term and the second term by the GCF. 20 20 ÷4 5 = 16 ÷ 4 = 4 16 Therefore, the simplest form of 20:16 is 5:4. 8 Let us have more examples: Example 1: Reduce the ratio 81:24 to lowest term Solution: The GCF of 81 and 24 is 3. 81 24 81 Answer: 24 = = 81 ÷3 24 ÷3 = 27 8 27 8 Example 2: There are 20 teachers to 520 students. What is the ratio of teachers to students? Express the ratio in lowest term. Solution: The GCF of 20 and 520 is 20. 20 20 ÷20 1 = 520 ÷20 = 26 520 Answer: 20 520 1 = 26 The order in which the ratio is expressed is important. Therefore, the order of the terms in a ratio must correspond to the order of objects being compared. In a ratio, a part can be compared to its whole. In the preceding example, the ratio of the number of boys to the total number of the students is 20 is to 36 and the ratio of the number of girls to the number of total students is 16 is to 36. If we compare the part to the total, the ratio of the part to the total has the same meaning as fraction. Example: Compare the number of vowels to consonants and vice versa in the following word using colon, fraction form and in words. ADORABLE Letters Number of Letters Vowels A, O, and E 3 Consonants D, R, B and L 4 Ratio of vowels to consonants: Using colon 3:4 Using fraction form 3 4 In words 3 to 4 9 Ratio of consonants to vowels: Using colon 4:3 Using fraction form 4 3 In words 4 to 3 Ratio of vowels and consonants to vowels: Using colon 7:3 Using fraction form 7 3 In words 7 to 3 In ratio, we compare two numbers or quantities with the same unit of measure. If these are in different units, they must be expressed in the same units. Examples: 1. 7 days to 3 weeks. Express in days (7days = 1 week) 7 days: 21 days or 7:21 or 1:3 in lowest term 2. 1 year to 4 months. Express in months (12 months = 1 year) 12 months: 4 months or 12:4 or 3:1 What’s More Use a sheet of paper in answering the following activities: A. Write each of the following as ratio in three forms. Express your answers in simplest form. Word Form Colon Form Fraction Form 1. 15 vases to 75 roses 2. 22 boys to 33 girls 3. 25 dogs to 45 cats 4. 10 meters to 400 centimeters 5. 18 hammers to 24 nails B. Read and answer the following problems. 1. Every quarter, each pupil submits 2 projects in Science. Give the ratio of projects to quarters. 2. There are 20 buses at a station. If each bus has 6 wheels, what is the ratio of buses to wheels? 10 What I Have Learned A ratio is a comparison of two values expressed as a word, a fraction or colon form. A ratio has two terms. In the ratio 6:10, the first term 6, is the numerator and is the number being compared. The second term 10 is the denominator and is the number to which the first number is being compared. Ratio is expressed in lowest term by dividing its Greatest Common Factors to the first term and second term such as: 6 10 3 or 5; 10 20 1 or 2; 12 36 1 or 3 In a ratio, the order in which the numbers or quantities is written is important. Example, the ratio of 5 white roses to 10 red ones is 5:10. This ratio is different from 10:5. What I Can Do Directions: Give the ratio of each of the following in three different ways. Reduce your answer in lowest term, if necessary. Write your answers in a separate sheet of paper. 1. atis to santol Word Form Colon Form 2. sipa ball to golf balls Fraction Form Word Form Colon Form Fraction Form 11 3. buttons to gems Word Form Colon Form 4. ribbons to marbles Fraction Form 5. sandwiches to orange juice Word Form Colon Form Fraction Form 7. skirts to blouses Word Form Colon Form Colon Form Colon Form Fraction Form 6. pencils to erasers Word Form Colon Form Fraction Form 8. pair of shoes to pair of socks Fraction Form 9. laptops to cellphones Word Form Word Form Word Form Colon Form Fraction Form 10. notebooks and bags to bags Fraction Form Word Form Colon Form Fraction Form 12 Lesson 2 Ratio and Proportion Using Concrete or Pictorial Models What’s In Directions: In a sheet of paper, write the following ratio in colon form and express your answers in simplest form. Colon Form 1. 6 baskets to 24 fruits 2. 48 plates to 32 glasses 3. 15 rooms to 480 pupils 4. 18 apples to 12 oranges 5. 9 pencils to 21 paper What’s New Read the word problem below and answer the questions that follow. Write your answers on a separate sheet of paper. Jane bought 5 pens for PhP60.00 and Jia bought 10 pens at PhP120.00 at Jahnel’s School Supplies Store. Give the ratio of pens to the amount of each child paid. PhP60.00 PhP120.00 13 Answer the following questions: 1. What did Jane and Jia buy? __________________________________________ 2. How many pens did each of them buy? ________________________________ 3. How much did each of them pay? ______________________________________ 4. What are being compared in the problem? _______________________________ What is It Let us go back to the word problem given. What are being compared? The number of pens and the amount each child paid. How can we show it? Number of pen Amount paid Jane 5 pens PhP60.00 Jia 10 pencils PhP120.00 We can write the two ratios in two ways: using colon form and fraction form. colon form 5:60 = 10:120 fraction form 5 10 = 120 60 5 is called the first term 60 and 10 are called means 60 is called the second term 5 and 120 are called extremes 10 is called the 3rd term means 120 is called the 4th term 5:60 = 10:120 extremes 14 What do you call two equal ratios? Two equal ratios form a proportion. In a proportion, the product of the means and the extremes are equal. In the previous example, 5:60 = 10:120 Means: 60 x 10 = 600 Extremes: 5 x 120 = 600 The products are the same so, 5:60 = 10:120 is a proportion. Here are more examples. The following pair of ratios form a proportion. 1. 3: 4= 15:20 means 3:4 = 15:20 3 15 = 20 4 extremes Means: Extremes: 4 x 15= 60 3 x 20 = 60 4 x 15 = 60 3 x 20 = 60 The products are the same so, 3: 4 = 15:20 is a proportion. 2. 5: 25= 10:30 means 5:25 = 10:30 5 25 10 = 30 extremes Means: Extremes: 25 x 10 = 250 5 x 30 = 150 25 x 10 = 250 5 x 30 = 150 The products are not the same so, 5: 25= 10:30 is not a proportion. If a given proportion, a term is missing, it can be solved using cross multiplication. 15 Examples: 1. 3:2 = 9:n 3 9 =𝑛 2 3xn=2x9 3𝑛 18 = 3 3 n= 6 means: 2 x 9 = 18 extremes: 3 x 6 = 18 2. n: 1 = 30:2 𝑛 30 = 2 1 n x 2 = 1 x 30 2𝑛 30 = 2 2 n = 15 means: 1 x 30 = 30 extremes: 15 x 2 = 30 Remember: If two ratios are equal, the two ratios form a proportion. A proportion is formed if the cross products of the two ratios are equal. What’s More Directions: In a sheet of paper, write Yes if each of the following forms a proportion and write No if it’s not. __________ 1. 2:3 = 4:6 __________ 6. 12:5 = 4:5 __________ 2. 4:5 = 8:9 __________ 7. 2:6 = 4:10 __________ 3. 3:7 = 4:9 __________ 8. 8:10 = 4:6 __________ 4. 6:7 = 24:28 __________ 9. 15:20 = 5:6 __________ 5. 2:5 = 4:12 __________ 10. 28:42 = 2:3 16 What I Have Learned A proportion is an equation stating that two ratios are equal. It can be written in fraction form or in colon form. 12 Example: fraction form colon form 14 6 =7 12:14= 6:7 12 is called the first term 14 and 6 are called means 14 is called the second term 12 and 7 are called extremes 6 is called the 3rd term means 7 is called the 4th term 12:14 = 6:7 extremes In a proportion, the first and last terms are called the extremes while the second and the third terms are called the means. What I Can Do Directions: Solve for the value of n in each proportion. __________ 1. n : 6 = 8 : 4 __________ 2. 6 : n = 3 : 10 __________ 3. 12 : 15 = 20 : n __________ 4. __________ 5. 4 2 𝑛 =8 𝑛 12 4 =3 17 II. Read and solve. 1. At the Bookstore, 5 pieces of Oslo paper cost PhP2.50. What is the cost of 30 pieces of Oslo paper? 2. Mrs. Juan’s family can consume 10 kilograms of rice in 5 days. How many kilograms of rice can they consume in 20 days? 3. Four pencils cost PhP32.00. What is the cost of 12 pencils? 4. Two kilograms of avocados cost PhP80.00. What is the cost of 6 kilograms of avocado? 5. Mariel saves PhP80.00 in 4 weeks. At this rate, how long will it take her to save PhP160.00? 18 Assessment Directions: Read each item carefully. Choose the best answer among the choices given and write the letter of the correct answer on your answer sheet. 1. What is the equivalent ratio of A. 1 to 5 1 5 in words? B. 2 to 5 C. 3 to 5 D. 4 to 5 C. 5 : 1 D. 4 : 3 2. What is the lowest term of the ratio 3 to 15? A. 3 : 4 B. 1 : 5 3. Write the ratio of A. 5 to 6 to B. 10 to 12 C. 6 to 5 D. 12 to 10 4. Which of the following is a correct proportion? A. 4:5 = 12:15 B. 1:2 = 3:4 C. 4: 6 = 7 : 8 D. 5: 9 = 10:12 5. What is the ratio of books to pupils if the teacher distributed 50 books to 25 pupils? A. 25 : 50 B. 1 : 5 C. 1 : 2 D. 2 : 1 6. What ratio can you form from the following pictures? A. 5 : 8 B. 8 : 5 C.10 : 16 D. 3 : 16 7. What proportion can you form from the following shapes? A. 6 : 2 = 2 : 1 B. 6 : 2 = 3 : 1 C. 2 : 6 = 1 : 2 D. 1 : 2 = 2 : 1 8. Each day Alaisa saves PhP20.00 and spends Php15.00. What is the ratio of her savings to her expenses? 19 A. 15 : 20 B. 5 : 20 C. 20 : 15 D. 1 :15 For numbers 9-10, refer to the following situation: There are 40 men, 25 women, and 30 children in a room. 9. What is the ratio of women to men? A. 30 : 25 B. 40 : 25 C. 25: 40 D. 25 : 30 C. 25 : 40 D. 30 : 25 10. What is the ratio of children to men? A. 30 : 40 B. 40 : 30 20 Answer Key 21 22 References Books: Adoracion M. Acuńa, Mathematics for Everyday Life Textbook for Grade Six, Quezon City, JTW Corporation Apistar, Elmer M. et.al, Soaring 21st Century Mathematics Grade 6, Second Edition, Quezon City,Philippines, Phoenix Publishing House, Inc. Frialde, Maysee B., Toward Excellence in Mathematics 6, pp.184-193 Lesson Guide in Elementary Mathematics Grade 6, Ateneo de Manila University, Book Media Press, Inc.,2010, pp .289-301 New Ways in Numbers, Teacher’s Edition Perez, M. et. al (2016). 21st Century Mathletes Textbook. Vibal Group Inc., pp. 82-91 Youtube /Youtube Pictures: https://www.dreamstime.com/set-five-multi-colored-pens-vector-illustration-set-fivemulti-colored-pens-image116318566 https://clipartix.com/ice-cream-cone-clipart-image-38168/ 23