1. 2-6 RATIOS, RATES & CONVERSIONS
Mrs. Caffey
MHS Algebra I
September 2012

2. VOCABULARY RATIO – a comparison of two numbers by division.
Example: The ratio of 3 to 5 can be expressed as:
3 to 5 3:5

3. VOCABULARY
RATE – ratio that compares quantities measured in different units
Example: $25 for 2 shirts
348 miles in 6 hours
UNIT RATE – rate with a denominator of 1
Example: $12.50 for 1 shirt
68 miles in 1 hour

4. EX #1: COMPARING UNIT RATES
You are shopping for shirts.
What store has the best deal?
$25 for 2 shirts $45 for 4 shirts $30 for 3 shirts
STEP 1: Write each STEP 2: Write
price as a ratio each as a unit rate

5. EX #2 CONVERTING UNITS 1. Choose a conversion factor & MULTIPLY
CONVERSION FACTOR: a ratio of 2 equivalent measures in different units such as
Convert 330 minutes to hours:
1. Choose a conversion
factor & MULTIPLY
it by the ORIGINAL amount
2. Cross out pairs of
matching units
3. Simplify
4. CLT

6. EX #2 CONVERTING UNITS 1. Choose a conversion factor & MULTIPLY
Convert 15 kg to grams
CONVERSION FACTOR:
1. Choose a conversion
factor & MULTIPLY
it by the ORIGINAL amount
2. Cross out pairs of
matching units
3. Simplify
4. CLT

7. STUDENTS TRY: 15 days to hours 11 lbs to ounces 5 liters to quarts
Convert the given amount to the given unit
15 days to hours
11 lbs to ounces
5 liters to quarts
25 km to cm

8. EX #3 CONVERTING BETWEEN SYSTEMS
The CN Tower in Canada is about 1815 ft tall. About how many METERS tall is it?
CONVERSION FACTOR: 1 m ft
1. Choose a conversion
factor & MULTIPLY
it by the ORIGINAL amount
2. Cross out
matching units
3. Simplify

9. EX #4 CONVERTING RATES 1. Write the speed as a ratio
A student ran the 50-yd dash in 5.8 seconds. At what speed did the student run in miles per hour?
CONVERSION FACTOR: 1 mile = 1760 yd
1. Write the speed as a ratio
Use Conversion to change
yards to miles
2. Cross out matching units
3. Use another conversion
to change seconds to hours
4. Simplify

10. EX #4 STUDENTS TRY 1. Write the speed as a ratio
A An athlete ran a sprint of 100 ft in 3.1 sec. At what speed was the athlete running in miles per hour?
CONVERSION FACTOR:
1. Write the speed as a ratio
Use Conversion to change
feet to miles
2. Cross out matching units
3. Use another conversion
to change seconds to hours
4. Simplify

11. HOMEWORK
Page 133
(#10-20 EVEN and
24-32 ALL, 34, 35)