Ratios Day 1 Presentation Problems 1. In Mr. Romero’s auto shop class, the ratio of boys to girls is 5:2. If there are 35 students in the class, how many are boys? Boys 5 5 5 5 5 = ? (25) = 35 Girls 5 5 7 units = 35 35 ÷ 7 = 5 1 unit = 5 5 units of 5 5 • 5 = 25 In Mr. Romero’s class, there are 25 boys. Milk It!? How many more boys are there than girls? 2. The Great Zucchini, an illusionist, has black rabbits and white rabbits which he pulls from his hat. The ratio of black rabbits to white rabbits is 1:3. If the Great Zucchini has 52 rabbits, how many of them are white? Black rabbits 13 = 52 White rabbits 13 13 13 = ? (39) 4 units = 52 52 ÷ 4 = 13 1 unit = 13 3 units of 13 3 • 13 = 39 The Great Zucchini has 39 white rabbits. Milk It! How many more white rabbits than black rabbits does he have? 3. Micah has a bag of 55 marbles, all blue and red. If the ratio of red to blue marbles is 3:2, how many red marbles does Micah have? How many blue marbles does he have? Blue marbles 11 11 5 units = 55 = ? (22) = 55 Red marbles 11 11 11 = ? (33) 55 ÷ 5 = 11 1 unit = 11 3 units of 11 3 • 11 = 33 Micah has 33 red marbles and 22 blue marbles. Milk It! What percent of the marbles are red? 2 units of 11 2 • 11 = 22 Ratios Day 1 Assessment Problems 1. Rachel drinks 128 ounces of fluids each day, some of which is water. The ratio she drinks of water to other drinks is 5:3. How many ounces of water does Rachel drink each day? Water 16 16 16 16 16 = ? (80) = 128 Other drinks 16 16 16 8 units = 128 128 ÷ 8 = 16 1 unit = 16 = 16 = 16 5 units of 16 5 • 16 = 80 Rachel drinks 80 ounces of water each day. 2. Mr. Edgett’s Algebra 2 class has both juniors and seniors. The ratio of juniors to seniors is 4:1. If he has 30 students, how many of them are juniors? Juniors 6 6 6 6 = ? (24) = 30 Seniors 6 5 units = 30 30 ÷ 5 = 6 1 unit = 6 = 16 16 of 6 4=units 4 • 6 = 24 Mr. Edgett has 24 juniors in his class.