5 Chapter Chapter 2 Ratio, Proportion, and Measurement

Section 5.1 Ratios

Write Ratios as Fractions. Objective A Write Ratios as Fractions.

Writing Ratios as Fractions A ratio is a quotient of two quantities. 1 to 2 or or 1 : 2 Writing a Ratio as a Fraction The order of the quantities is important when writing ratios. To write a ratio as a fraction, write the first number of the ratio as the numerator of the fraction and the second number as the denominator. Objective A

Example Write the ratio 15 to 23 using fractional notation. Objective A Continued

Example Write the ratio of $25 to $15 as a fraction in simplest form. Objective A Continued

Example Write the ratio of 10.3 to 15.1 using fractional notation. Objective A Continued

Example Write the ratio of 2.6 to 3.1 as a fraction in simplest form. Objective A Continued

Example Write the ratio of 2 2/3 to 1 13/15 as a fraction in simplest form. Objective A Continued

Example Given the rectangle shown: a. Find the ratio of its width to its length. b. Find the ratio of its length to its perimeter. a. b. Perimeter = 7 + 5 + 7 + 5 = 24 feet 7 feet 5 feet Objective A Continued

Write Rates as Fractions. Objective B Write Rates as Fractions.

Writing Rates as Fractions A special type of ratio is a rate. A rate is used to compare different kinds of quantities. Objective A

Example Write the rate as a fraction in simplest form. 10 nails every 6 feet Objective A Continued

Example Write each rate as a fraction in simplest form. 1. $2160 for 12 weeks 2. 360 miles on 16 gallons of gasoline Objective A Continued

Objective C Find Unit Rates.

Finding Unit Rates A unit rate is a rate with a denominator of 1. 55 miles per hour is an example of a unit rate. Write a Rate as a Unit Rate To write a rate as a unit rate, divide the numerator of the rate by the denominator. Objective A Continued

Example Write as a unit rate: $31,500 every 7 months The unit rate is Objective A Continued

Objective D Find Unit Prices.

Finding Unit Prices A unit rate is “money per item,” it is also called a unit price. Objective A Continued

Example A store charges $4.80 for a 32-ounce container of laundry soap. What is the unit price in dollars per ounce? Objective A Continued

Example Approximate each unit price to decide which is the better buy: 4 bars of soap for $0.99 or 5 bars of soap for $1.19. Objective A Continued Thus the 5-bar package is the better buy.