Unit 2 Section 9 Conversions.notebook
Rates, Ratios and Conversions
January 02, 2013
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Rates and Ratios
Ratio ­ a comparison of two numbers. (ratio must be in the same units)
Examples: 5 to 3 5:3 5
3
Rate ­ a ratio that compares two unlike terms
Example: 180 miles 3 hours Unit Rate ­ the rate for one unit of a given quantity
Example: 180 miles the unit rate is 60 miles or 60 mi/h
1 hour
3 hours
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Example 1: What is the better buy, 6 bagels for $3.29 or 8 bagels for $4.15?
Unit 2 Section 9 Conversions.notebook
January 02, 2013
To convert from one unit to another, such as feet to inches, you multiply the original unit by a conversion factor that produces the desired unit.
A conversion factor is a ratio of two equivalent measure in different units.
1 ft
A conversion factor is always equal to 1, such as .
12 in
Take out your formula sheets for a list of common equivalent units of measure.
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Example 2: What is the given amount converted to the given units?
(Use a conversion factor!)
a) 330 min; hours
b) 15 kg; grams
c) 3 yards; inches
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Example 3: The CN Tower in Toronto, Canada, is about 1815 ft tall. About how many meters tall is the tower? Use the fact that 1 m ≈ 3.28 ft.
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Example 4: A student ran the 50­yd dash in 5.8 s. At what speed did the student run in miles per hour? Round your answer to the nearest tenth. (1 mi = 1760 yd)
Unit 2 Section 9 Conversions.notebook
January 02, 2013
Example 5: What is the given amount converted to the given units?
a) 2 qt/min = __ gal/s
b) 2.2 kg = ___ lb
(1 g = .0022 lb)
c) 60 ft/s = ___ km/h
(1 ft = .3048 m)