1. Ch 3.8 Objective: To compare ratios and rates.

2. Definitions Ratio: A comparison of two whole numbers in the same units. Rate: A comparison of two numbers with different units.

3. RatioRate - a comparison of two whole numbers in the same units. - a comparison of a number to one in different units. - always written as two numbers. - always written as a single number on a per unit basis. - never write the units.- always write the units. - reduce to simplify.- divide to simplify.

4. Ratio 5 girls to 7 boys 4 Possible Ways to Write a Ratio 5 out of 12 is the ratio that represents 5 girls out of 12 students

5. Ratio 1) 2) 3) 4) 5) 6)

6. Rate. 1) 84 students in 4 classrooms 2) $30 for 8 lunches 3) 15,000 cars sold by 2000 dealers

7. Reciprocal Rates 8 oranges for 2 dollars Unit RateReciprocal Rate $87.50 for 5 tickets Unit RateReciprocal Rate

8. Rate Multiplication Your heart beats 70 beats/min. How many beats per hour is this? StartFinish Rates

9. Rate Multiplication Joe reads 12 pages per day. How long would it take him to read a 684 page book? StartFinish Rates

10. Rate Multiplication The world record for the 100 yard dash is 9.4 seconds. How fast is this in miles/hr? StartFinish Rates