Common Core Learning Standards GRADE 7 Mathematics RATIOS & PROPORTIONAL RELATIONSHIPS Common Core Learning Standards Analyze proportional relationships and use them to solve real-world and mathematical problems. Concepts Unit Rate Embedded Skills Solve unit rate problems that have fractional quantities. (Problems may require solving complex fractions). Solve ratio problems whose quantities are lengths of the same unit and different units. 7.RP.1 Compute unit rates associated with ratios of fractions, including ratios of lengths, areas and other quantities measured in like or different units. For example, if a person walks 1/2 mile in each 1/4 hour, compute the unit rate as the complex fraction 1/2/1/4 miles per hour, equivalently 2 miles per hour. Vocabulary Ratio Complex fraction Unit rate Rate Proportion equivalent Solve ratio problems whose quantities are areas of the same unit and different units. Solve ratio problems of other quantities with the same unit and different units. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Divide two fractions by taking the reciprocal of the divisor. Compute the unit rate. SAMPLE TASKS I. If 5 tomatoes cost $2.00, what is the unit price of the tomatoes? How much would a dozen tomatoes cost? II. Whitney earns $206.25 for 25 hours of work. How much does Whitney earn per hour? At this rate, how much does Whitney earn in 30 hours? Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. III. A trail mix recipe calls for 1/3 pound of mixed nuts, 4/15 pound of raisins, and 2/5 pounds of granola. What is the ratio of raisins to mixed nuts in simplest form. IV. An artist made purple paint by mixing ½ quart of red paint and ¾ quart of blue paint. What is the ratio of red paint to blue paint in simplest form. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. V. Franklin walked ½ mile in 8 ½ minutes. What is the unit rate in miles per minute. Common Core Learning Standards Analyze proportional relationships and use them to solve real-world and mathematical problems. 7.RP.2a. Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin. Concepts Embedded Skills Proportional Relationships Calculate the cross product to determine if the two ratios are in proportion (equivalent). Analyze ratios in a table to determine if the ratios are equivalent by finding the constant of proportionality (slope). Graph ratios on a coordinate plane to determine if the ratios are proportional by observing if the graph is a straight line through the origin (y = mx, where m is the slope/constant of proportionality). Solve proportions by cross multiplication. Vocabulary constant of proportionalit y rate of change slope cross product equivalent origin quantities Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Write and solve proportions. SAMPLE TASKS I. A Is ∆ABC similar to ∆DEF? Use the constant of proportionality in your reasoning. D 6 cm 10 cm B C 8 cm 12cm E 20 cm 16cm F Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Height of Rockets A) Which rocket is traveling at a proportional speed? How can you tell? 80 Height (ft.) 70 60 KEY 50 Rocket A 40 Rocket B 30 B) What is the constant of proportionality of that rocket? 20 10 0 ________________ 0 1 2 3 4 5 Time after launch (sec.) 6 7 8 C) After how many seconds are the rockets at the same height? How can you tell? How high are they? Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Common Core Learning Standards Analyze proportional relationships and use them to solve real-world and mathematical problems. 7.RP.2b. Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships. Concepts Embedded Skills Constant of Calculate the constant of proportionality/unit rate proportionality from a table or diagram. Compute the rate of change/slope from a graph (rise over run) or equation (m in y=mx). Calculate the constant of proportionality/unit rate given a verbal description of a proportional relationship. Vocabulary constant of proportionality unit rate slope proportional relationship rate of change direct proportional relationship SAMPLE TASKS Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Use the graph at the left to help you answer the following questions. 7 6 1. Explain why it is or is not a proportional relationship. Cost (in Dollars 5 4 2. What is the constant of proportionality? ____________ 3 2 3. Write the equation of the line?_____________________ 1 4. How would you determine how much it would cost for 7 roses? 0 0 1 2 3 4 5 6 7 Number of Roses Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Use the graph at the left to help you answer the following questions. 1. Explain why it is or is not a proportional relationship. 2. What is the constant of proportionality?_______________ 3. Write the equation of the line?_______________________ 4. How many times would the parrots heart beat in 10 minutes? How do you know? Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Common Core Learning Standards Concepts Embedded Skills Analyze proportional relationships and use them to solve real-world and mathematical problems. Proportional relationships and equations Write an equation from a proportional relationship. Solve equations created from proportional relationships. 7.RP.2c. Represent proportional relationships by equations. For example, if total cost t is proportional to the number n of items purchased at a constant price p, the relationship between the total cost and the number of items can be expressed as t = pn. Vocabulary proportional relationships equation rate ratio SAMPLE TASKS I. Raffle tickets cost $3 each. Write an equation that shows the total cost c of buying r raffle tickets. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. II. The speed limit on a highway is 65 miles per hour. Write an equation that shows the number of miles driven, d , in t hours. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Common Core Learning Standards Concepts Analyze proportional relationships and use them to solve real-world and mathematical problems. Relationships and proportional relationships 7.RP.2d. Explain what a point (x, y) on the graph of a proportional relationship means in terms of the situation, with special attention to the points (0, 0) and (1, r) where r is the unit rate. Embedded Skills Define the rate of proportionality from a graph. Explain the meaning of a point on a graph y=mx of a real life situation. Vocabulary Calculate the unit rate by identifying that on a graph when the x-coordinate is 1, the y-coordinate is the unit rate. rate of proportionalit y x-coordinate y-coordinate unit rate SAMPLE TASKS A) Describe in a sentence what point A (10,12) represents on this graph? A (10,12) B) Identify the unit rate and describe what it means? Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. Common Core Learning Standards Onds Analyze proportional relationships and use them to solve real-world and mathematical problems. 7.RP.3. Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error. Concepts ratios, percents, and proportions Embedded Skills Solve multistep ratio problems using proportions. Focus on simple interest, tax, markups/downs, gratuities and commissions, fees, percent increase/decrease, and percent error. Solve multistep percent problems using proportions. Focus on simple interest, tax, markups/downs, gratuities and commissions, fees, percent increase/decrease, and percent error. Vocabulary Ratio Proportion Percent SAMPLE TASKS I. Dan takes a loan for $2000 for two years. If the interest rate is 6%, determine how much money will be paid back in total. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. ii. A car costs $21,949. If the tax rate is 7.5%, find the total cost of the car. III. KIx sneakers are sold at two different stores. At The Sneaker Outlet, the cost is $60.00 but they are on sale for 15% off. At The Sneaker Barn, the cost is $66.00 but they are on sale for 25% off. Determine which pair of sneakers is cheaper and how much would saved compared to the other store. IV. A group of 4 friends went to a restaurant. The bill came to a total of $75.00 . If a gratuity is 20% is added to the bill, how much would each person pay if the bill was split evenly. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only. V. The price of a Barry Bonds baseball card in 2001 was $50. It is now being sold for $30. Find the percent decrease in the cost of the card. VI. The 2010 census of Buffalo was estimated to be 400,000 residents. The actual count was 376,908. Find the relative error to the nearest tenth of a percent. Copyright (c) 2011 by Erie 1 BOCES- Deep Curriculum Project for Mathematics-- Permission to use (not alter) and reproduce for educational purposes only.