6th Grade– CCGPS Math LFS Unit 2: Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Standards: Cluster: Understand ratio concepts and use ratio reasoning to solve problems. MCC6.RP.1 (DOK 2) Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, “The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak.” “For every vote candidate A received, candidate C received nearly three votes.” MCC6.RP.2 (DOK 2) Understand the concept of a unit rate a/b associated with a ratio a: b with b ≠ 0 (b not equal to zero), and use rate language in the context of a ratio relationship. For example, "This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is 3/4 cup of flour for each cup of sugar." "We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger." MCC6.RP.3 (DOK 2) Use ratio and rate reasoning to solve real‐world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations. a. Make tables of equivalent ratios relating quantities with whole‐number measurements, find missing values in the tables, and plot the pairs of values on the coordinate plane. Use tables to compare ratios. b. Solve unit rate problems including those involving unit pricing and constant speed. For example, If it took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? c. Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole given a part and the percent. d. Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities. Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 1 K-U-D Unit 2: Rate, Ratio and Proportional Reasoning Using Equivalent Fractions UNDERSTAND… By the end of the unit, I want my students to understand… ratio concepts and use ratio reasoning to solve real world problems. Know The concept of a ratio is a way of expressing relationships between quantities. (RP.1) A rate is a special ratio that compares two quantities with different units of measure. (RP.2) Do Distinguish when a ratio is describing part to part or part to whole comparison. (RP.1) DOK2 Describe ratio relationships between two quantities. (RP.1) DOK1 Unit rates are the ratio of two measurements in which the second term is one (e.g., x miles per one hour). (RP.2) Translate relationships between two quantities using the notation of ratio language (1:3, 1 to 3, 1/3). (RP.1) DOK1 When using rates a/b, “b” cannot be 0 (because division by 0 is undefined). (RP.2) Communicate relationships between two quantities using ratio notation and language. (RP.1) DOK2 Rate language (per, each, or the @ symbol). (RP.2) Solve problems involving ratios. (RP.2) DOK1 Correctly use ratio notation and models to represent relationships between quantities. (RP.2) DOK2 Make, complete, and read a table of equivalent ratios. (RP.3a) DOK2 Use a table to compare ratios. (RP.3a) DOK2 Determine missing values using ratio reasoning. (RP.3a) DOK2 Identify relationships in ratio tables. (RP.3a) DOK2 Plot pairs of values from a table to a coordinate plane. (RP.3a) DOK1 Tools such as tables of equivalent ratios, tape diagrams, double number line diagrams, and equations support the development of ratio and rate reasoning. (RP.3a and 3b) Pairs of values from a table can be plotted on the coordinate plane. (RP.3a) The connections between tables and plotted points on the coordinate plane allow for extended reasoning and synthesis of the concept of ratios and rates. (RP.3a) Rate problems compare two different units, such as miles to hours. (RP.3b) A unit occurs when at least one of the units is one. (RP.3b) Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 2 The connections between tools allow for extended reasoning and synthesis of the concept of ratios and rates (e.g., How do tape diagrams and double number lines show rate reasoning given the same context?). (RP.3b and 3c) A percent is a rate per 100 and can be represented using tools such as tables of equivalent ratios, tape diagrams, double number line diagrams, and equations. (RP.3c) Solve real-world problems using rate reasoning (RP.3b) DOK2 Calculate the unit rate. (RP.3b) DOK1 Write a percent as a rate over 100. (RP.3c) DOK1 Find the percent of number using rate methods developed in 6.RP.3b. (RP.3c) DOK1 Given the parts and a percent, determine the whole using tools: tape diagrams, double number lines). (RP.3c) DOK2 Percentage-based rate problems compare two different units where one of the units is 100. (RP.3c) Represent the relationship of part to whole to describe percent using models. (RP.3c) DOK2 Measurement units employ ratio reasoning (e.g., If 3 feet is equal to one yard, then 6 feet is equal to 2 yards). (RP.3d) Convert customary units using ratio tools and Vocabulary: (RP.1): Rate; Ratio; Relationship; Rational Number (RP.2): Unit Rate; (RP.3) a: Equivalent Ratios; Proportion; X Y Table; Ordered Pairs; Coordinate Plane; c: Percent; Tape Diagram d: Tape Diagram; Convert; Customary Units of Measure; Metric Units of Measure; Double Number Line Diagrams Douglas County School System methods. (RP.3d) DOK1 Convert metric units by multiplying or dividing by powers of ten. (RP.3d)DOK1 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Represent relationships between measurement units using tables of equivalent ratios, tape diagrams, double number line diagrams, and equations. (RP.3d) DOK2 2/9/2016 Page 3 SLM Unit 2: Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Key Learning Concept Concept Concept Lesson EQ’s Lesson EQ’s Lesson EQ’s 1. Vocabulary Douglas County School System 1. Vocabulary 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Vocabulary 2/9/2016 Page 4 Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 5 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6.RP.1 What does this standard mean? Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, “The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak.” “For every vote candidate A received, candidate C received nearly three votes.” A ratio is the comparison of two quantities or measures. The comparison can be part-towhole (ratio of guppies to all fish in an aquarium) or part-to-part (ratio of guppies to goldfish). 6 Students need to understand each of these ratios when expressed in the following forms: , 15 2 6 to 15 or 6:15. These values can be reduced to , 2 to 5 or 2:5; however, students would 5 need to understand how the reduced values relate to the original numbers. Mathematical Practice Examples and Explanations A ratio is a comparison of two quantities which can be written as a to b, Standards a , or a:b. b A rate is a ratio where two measurements are related to each other. When discussing measurement of different units, the word rate is used rather than ratio. Understanding rate, however, is complicated and there is no universally accepted definition. When using the term rate, contextual understanding is critical. Students need many opportunities to use models to demonstrate the relationships between quantities before they are expected to work with rates numerically. 6.MP.2. Reason abstractly and quantitatively. 6.MP.6. Attend to precision. A comparison of 8 black circles to 4 white circles can be written as the ratio of 8:4 and can be regrouped into 4 black circles to 2 white circles (4:2) and 2 black circles to 1 white circle (2:1). Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 6 Students should be able to identify all these ratios and describe them using “For every…., there are …” Suggested Instructional Strategy Using a variety of situations, describe relationships using ratio, for example: 1. Part to part: Compare the number of girls to boys in the classroom using the different symbols for ratio (girls: boys, girls to boys, 𝑔𝑖𝑟𝑙𝑠/𝑏𝑜𝑦𝑠, girls out of boys). Then compare the number of boys to girls in the same way. 2. Part to whole: Compare the number of girls to the whole class. Do the same thing for the boys in the class. Skill Based Task There are four dogs and three cats. What is the ratio of dogs to cats and cats to dogs? Instructional Resources/Tools Problem Task The newspaper reported, “For every vote candidate A received, candidate B received three votes.” Describe possible election results using at least three different ratios. Explain your answer. Ratio coloring activity: http://www.softschools.com/math/ratios/ratio_coloring_game/ Internet Resources: https://ccgps.org/6.RP.html Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 7 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6.RP.2 What does this standard mean? Understand the concept of a unit rate a/b associated with a ratio a:b with b 0, and use rate language in the context of a ratio relationship. For example, “This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is ¾ cup of flour for each cup of sugar.” “We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger.”1 A unit rate expresses a ratio as part-to-one. For example, if there are 2 cookies for 3 students, 2 2 each student receives of a cookie, so the unit rate is :1. If a car travels 240 miles in 4 3 3 hours, the car travels 60 miles per hour (60:1). Students understand the unit rate from various contextual situations. Examples and Explanations A unit rate compares a quantity in terms of one unit of another quantity. Students will often use unit rates to solve missing value problems. Cost per item or distance per time unit are common unit rates, however, students should be able to flexibly use unit rates to name the amount of either quantity in terms of the other quantity. Students will begin to notice that related unit rates are reciprocals as in the first example. It is not intended that this be taught as an algorithm or rule because at this level, students should primarily use reasoning to find these unit rates. Mathematical Practice Standards 6.MP.2. Reason abstractly and quantitatively. 6.MP.6. Attend to precision. In Grade 6, students are not expected to work with unit rates expressed as complex fractions. Both the numerator and denominator of the original ratio will be whole numbers. Examples: On a bicycle you can travel 20 miles in 4 hours. What are the unit rates in this situation, (the 1 Expectations for unit rate in this grade are limited to non-complex fractions. Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 8 distance you can travel in 1 hour and the amount of time required to travel 1 mile)? Solution: You can travel 5 miles in 1 hour written as written as 1 hr 5 1 mi 5 mi 1 hr and it takes 1 5 of a hour to travel each mile . Students can represent the relationship between 20 miles and 4 hours. 1 mile 1 hour A simple modeling clay recipe calls for 1 cup corn starch, 2 cups salt, and 2 cups boiling water. How many cups of corn starch are needed to mix with each cup of salt? Suggested Instructional Strategy 1. Show examples of rates: 300 miles on 10 gallons of gas, $15 for 5 ounces, $30 for 6 hours. 2. Connect rates from number 1 with their unit rates: 30 miles per gallons, $3 per 1 ounce, $5 per 1 hour. 3. Convert rates from fraction form to written form using per, each, or @. Example 300 𝑚𝑖𝑙𝑒𝑠10 𝑔𝑎𝑙𝑙𝑜𝑛𝑠 𝑜𝑓 𝑔𝑎𝑠 = 30 miles per gallon of gas. 4. Quick write: Students brainstorm examples of unit rates in the real world (e.g., 4 candy bars per $1, 55 miles per hour, 6 points per touchdown). Skill Based Task Identify (given examples) the difference between a ratio and a rate. Instructional Problem Task Is the following example a ratio or rate? [60 heartbeats per minute] Explain your answer. UEN- Lesson “Ratio, Rate, and Proportion” Activities 1 and 2 from http://mypages.iit.edu/~smart/dvorber/lesson3.htm Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 9 Resources/Tools CCGPS Internet Resources: https://ccgps.org/6.RP_K1IV.html Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 10 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6.RP.3 What does this standard mean? Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations. a. Make tables of equivalent ratios relating quantities with wholenumber measurements, find missing values in the tables, and plot the pairs of values on the coordinate plane. Use tables to compare ratios. Ratios and rates can be used in ratio tables and graphs to solve problems. Previously, students have used additive reasoning in tables to solve problems. To begin the shift to proportional reasoning, students need to begin using multiplicative reasoning. To aid in the development of proportional reasoning the cross-product algorithm is not expected at this level. When working with ratio tables and graphs, whole number measurements are the expectation for this standard. Examples and Explanations For example, At Books Unlimited, 3 paperback books cost $18. What would 7 books cost? How many books could be purchased with $54. To find the price of 1 book, divide $18 by 3. One book is $6. To find the price of 7 books, multiply $6 (the cost of one book times 7 to get $42). To find the number of books that can be purchased with $54, multiply $6 times 9 to get $54 and then multiply 1 book times 9 to get 9 books. Students use ratios, unit rates and multiplicative reasoning to solve problems in various contexts, including measurement, prices, and geometry. Notice in the table below, a multiplicative relationship exists between the numbers both horizontally and vertically. (Red numbers indicate solutions.) Mathematical Practice Standards 6.MP.1. Make sense of problems and persevere in solving them. 6.MP.2. Reason abstractly and quantitatively. 6.MP.4. Model with mathematics Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 11 6.MP.5. Use appropriate tools strategically. Students use tables to compare ratios. Another bookstore offers paperback books at the prices below. Which bookstore has the best buy? Explain how you determined your answer. 6.MP.7. Look for and make use of structure. To help understand the multiplicative relationship between the number of books and cost, students write equations to express the cost of any number of books. Writing equations is foundational for work in 7th grade. For example, the equation for the first table would be C = 6n. The numbers in the table can be expressed as ordered pairs (number of books, cost) and plotted on a coordinate plane. Students are able to plot ratios as ordered pairs. For example, a graph of Books Unlimited would be: Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 12 Suggested Instructional Strategy 1. Have students make a table given a ratio situation. They should plot those points on a coordinate plane and draw conclusions about what’s happening in the ratio situation. 2. Give students a table with missing values and have them identify the missing values. 3. Have students study ratio relationships in a table. Skill Based Task Problem Task Analyze the table below to determine the missing values. Graph the information from the table on the coordinate plane Fill in the missing values on the table below. and explain the relationship of swimmers to life guards. Swimmers 20 30 40 60 90 100 Life Guards 2 3 4 6 CCGPS Internet Resources: https://ccgps.org/6.RP.3.html Instructional http://www.youtube.com/watch?v=d625kdtsUIw Resources/Tools UEN: Price-Earnings ratio http://www.uen.org/Lessonplan/preview.cgi?LPid=25290 Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 13 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6.RP.3b What does this standard mean? b. Solve unit rate problems including those involving unit pricing and constant speed. For example, if it took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? At what rate were lawns being mowed? Students recognize the use of ratios, unit rate and multiplication in solving problems, which could allow for the use of fractions and decimals. Examples and Explanations The ratio tables (in 6.RP.3a) use unit rate by determining the cost of one book. However, ratio tables can be used to solve problems without the use of a unit rate. For example, in trail mix, the ratio of cups of peanuts to cups of chocolate candies is 3 to 2. How many cups of chocolate candies would be needed for 9 cups of peanuts? One possible way to solve this problem is to recognize that 3 cups of peanuts times 3 will give 9 cups. The amount of chocolate will also increase at the same rate (3 times) to give 6 cups of chocolate. Students could also find the number of cups of chocolate candies for 1 cup of peanuts by dividing both Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Mathematical Practice Standards 6.MP.1. Make sense of problems and persevere in solving them. 6.MP.2. Reason abstractly and quantitatively. 6.MP.4. Model with mathematics 6.MP.5. Use appropriate tools strategically. 6.MP.7. Look for and make use of structure. 2/9/2016 Page 14 sides of the table by 3, giving 2 3 cup of chocolate for each cup of peanuts. To find the amount of 2 3 chocolate needed for 9 cups of peanuts, students multiply the unit rate by nine (9 • ), giving 6 cups of chocolate. Suggested Instructional Strategy 1. Identify the question being asked based on the context, and determine a method for finding the unit rate (table of equivalent ratios, tape diagrams, double number line diagrams, and equations). 2. Complete the determined tool to find the unit rate (e.g., use tool to find the ratio in which one of the units is one). Skill Based Task If 5 CDs cost $60, what is the price of each CD? Problem Task Joe’s Gas and Go has drinks for the following prices: 12 fl. oz. for $ .89 16 fl. oz. for $ .99 20 fl. oz. for $1.09 32 fl. oz. for $1.19 Which drink costs the least per ounce? You may round to the nearest cent and use a calculator if you desire. Instructional Resources/Tools Illuminations measuring up activity: http://illuminations.nctm.org/LessonDetail.aspx?ID=L511 CCGPS Internet Resources: https://ccgps.org/6.RP.3_KNQI.html Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 15 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6RP.3c What does this standard mean? c. Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent. This is the students’ first introduction to percent. Percentages are a rate per 100. Models, such as percent bars or 1010 grids should be used to model percent. Examples and Explanations Students use percentages to find the part when given the percent, by recognizing that the whole is being divided into 100 parts and then taking a part of them (the percent). For example, to find 40% of 30, students could use a 1010 grid to represent the whole (or 30). If the 30 is divided into 100 parts, the rate for one block is 0.3. Forty percent would be 40 of the blocks, or 40 0.3, which equals 12. Student also find the whole, given a part and the percent. For example, if 25% of the students in Mrs. Rutherford’s class like chocolate ice cream, then how many students are in Mrs. Rutherford’s class if 6 like chocolate ice cream? Students can reason that if 25% is 6 and 100% is 4 times the 25%, then 6 times 4 would give 24 students in Mrs. Rutherford’s class. Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions Mathematical Practice Standards 6.MP.1. Make sense of problems and persevere in solving them. 6.MP.2. Reason abstractly and quantitatively. 6.MP.4. Model with mathematics 6.MP.5. Use appropriate tools strategically. 6.MP.7. Look for and make use of structure. 2/9/2016 Page 16 Suggested Instructional Strategy 1. Model using a hundreds grid. Color in 30 units and have students write it as a fraction and percent. 2 Use double number lines and tape diagrams in which the whole is 100 to find the rate per hundred. Skill Based Task What is 25% of 60? 72% of what number is 300? Instructional Resources/Tools Problem Task Stop and Shop has pants for $30 with a 10% discount, while Stay and Shop has pants for $45 with a 20% discount. Which store has the pants for a better price? Use a table of equivalent values, double number line, or tape diagram to solve and explain your reasoning. Coloring percent activity: http://www.softschools.com/math/percent/games/ NLVM percent virtual manipulative: http://nlvm.usu.edu/en/nav/frames_asid_160_g_2_t_1.html Tape Diagrams: http://mathgpselaboration.blogspot.com/2010/04/mp5-tape-diagrams.html CCGPS Internet Resources: https://ccgps.org/6.RP.3_MGB2.html Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 17 Domain: Cluster: Ratios and Proportional Relationships Understand ratio concepts and use ratio reasoning to solve problems MCC6.RP.3d What does this standard mean? d. Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities. A ratio can be used to compare measures of two different types, such as inches per foot, milliliters per liter and centimeters per inch. Students recognize that a conversion factor is a fraction equal to 1 since the quantity described in the numerator and denominator is the same. Mathematical Practice Examples and Explanations For example, 12 inches 1 foot Standards is a conversion factor since the numerator and denominator name the same amount. Since the ratio is equivalent to 1, the identity property of multiplication allows an amount to be multiplied by the ratio. Also, the value of the ratio can also be expressed as 1 foot 12 inches allowing for the conversion ratios to be expressed in a format so that units will “cancel”. 6.MP.1. Make sense of problems and persevere in solving them. 6.MP.2. Reason abstractly and quantitatively. Students use ratios as conversion factors and the identity property for multiplication to convert ratio units. 6.MP.4. Model with mathematics For example, how many centimeters are in 7 feet, given that 1 inch = 2.54 cm. 6.MP.5. Use appropriate tools strategically. 7 feet 12 inches 2.54 cm 12 inches 2.54 cm 7 feet 7 12 2.54 cm 213.36 cm 1foot 1 inch 1 foot 1 inch Note: Conversion factors will be given. Conversions can occur both between and across the metric and English system. Estimates are not expected. 6.MP.7. Look for and make use of structure. Suggested Instructional Strategy 1. Use double number line, tape diagrams, tables of equivalent values, or equations to convert measurements in customary and metric units. Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 18 2. If 4 cups equals one quart, how many cups in 12 quarts? 4 𝑐𝑢𝑝𝑠/1 𝑞𝑢𝑎𝑟𝑡 = 𝑥 𝑐𝑢𝑝𝑠/12 𝑞𝑢𝑎𝑟𝑡𝑠 Skill Based Task How many inches are in three feet? How many inches in two miles? Instructional Resources/Tools Problem Task In the store a package of candy that weighs 150 grams costs $1.00. A package of 200 candies that each weigh 200 milligrams also costs $1.00. Which package is the better deal? NLVM conversion manipulative: http://nlvm.usu.edu/en/nav/frames_asid_272_g_2_t_4.html?open=instructions&from=category_g_2_t_4.ht ml CCGPS Internet Resources: https://ccgps.org/6.RP.3_3VMF.html Douglas County School System 6th Grade Math Unit 2 Rate, Ratio and Proportional Reasoning Using Equivalent Fractions 2/9/2016 Page 19