Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Unit 3
Chapter 4 Section 1
Ratios
Objective: To write ratios and use them to compare quantities
Ratio: a comparison of two quantities by division
You can write a ratio in three ways: 5 to 7
5:7
5
7
All three forms are acceptable, but we write them most often as a fraction.
Ratios need to use the same units.
Equivalent Ratio: two ratios that are equal
Equivalent ratios are the same as equivalent fractions.
Jun 6­8:17 PM
1
Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Examples:
Writing Ratios:
Use the table to answer questions 1 ­ 3: Write each ratio as a fraction in simplest form.
1) Tigers wins to Tigers losses
Wins Losses
Panthers
12
6
Leopards
9
9
8
6
10
12
Lions
2) Leopards wins to Leopards losses
Tigers
3) Lions wins to Tigers wins
Writing Equivalent Ratios
4) Find a ratio equivalent to 4
5
5) Find a ratio equivalent to 1
8
6) Write the ratio 2 yd to 20 ft as a fraction in simplest form.
7) Write the ratio 3 gal to 10 qt as a fraction in simplest form.
Comparing Ratios
8) An official U.S. flag has a length­to­width ratio of 19 : 10. the largest U.S. flag measures 505 ft by 255 ft. Is this an official U.S. flag?
Hint: You can use decimals to express and compare ratios.
Tell whether the ratios are equivalent or not equivalent.
9) 7 : 3, 128 : 54
10) 6.1 to 7, 30.5 to 35
11) 180 , 25
240
34
Write in simplest form.
12) 2.4
16
13)
8.5
15
Jun 10­10:28 AM
2
Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Challenge
A bag contains colored marbles. The ratio of red marbles to blue marbles is 1 : 4. The ratio of blue marbles to yellow marbles is 2 : 5. What is the ratio of red marbles to yellow marbles?
Jul 26­12:40 PM
3
Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Error Analysis
Your math class includes 15 girls and 10 boys. Two new students, a girl and a boy, join the class. Your friend says the ratio of girls to boys is the same as before. Explain your friends error.
Jun 19­9:19 AM
4
Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Dec 1­8:35 AM
5
Unit 3 Chapter 4 Section 1 Ratios.notebook
December 01, 2015
Homework
Textbook Pages 130 & 131, #'s 12 - 38 even
Jun 10­11:05 AM
6