A comparison of two numbers is called a ratio.

Transcription

1 A comparison of two numbers is called a ratio.

2 Here are two numbers: 3 and 4

3 Here are two numbers: 3 and 4 We may write: 3 to 4

4 Here are two numbers: 3 and 4 We may write: 3 to 4 3:4

5 Here are two numbers: 3 and 4 We may write: 3 to 4 3:4 3 4

6 Here are two numbers: 75 and 100

7 Here are two numbers: 75 and 100 We may write: 75 to 100

8 Here are two numbers: 75 and 100 We may write: 75 to :100

9 Here are two numbers: 75 and 100 We may write: 75 to :

10 We often choose to write ratios in lowest terms = 3 4

11 A chewing gum company used to state, "Four out of five dentists recommend our sugarless gum for their patients that chew gum."

12 A chewing gum company used to state, "Four out of five dentists recommend our sugarless gum for their patients that chew gum." Probably more than five dentists were interviewed.

13 Ratios are often used to compare quantities.

14 Ratios are often used to compare quantities. Such as: 3 feet to 4 feet

15 Ratios are often used to compare quantities. Such as: 3 feet to 4 feet 3 miles to 4 miles

16 Ratios are often used to compare quantities. Such as: 3 feet to 4 feet 3 miles to 4 miles 3 kg to 4 kg

17 3 feet to 4 inches is not a ratio.

18 3 feet to 4 inches is not a ratio. 3 feet 4 inches

19 3 feet to 4 inches is not a ratio. 3 feet 4 inches = 36 inches 4 inches

20 3 feet to 4 inches is not a ratio. 3 feet 4 inches = 36 inches 4 inches

21 3 feet to 4 inches is not a ratio. 3 feet 4 inches = 36 inches 4 inches 9 1

22 We have interviewed 42 Chicago baseball fans. Twenty-four stated they were Sox fans and eighteen stated they were Cubs fans.

23 We have interviewed 42 Chicago baseball fans. Twenty-four stated they were Sox fans and eighteen stated they were Cubs fans. The ratio of Sox fans to Cubs fans is 24:18

24 We have interviewed 42 Chicago baseball fans. Twenty-four stated they were Sox fans and eighteen stated they were Cubs fans. The ratio of Sox fans to Cubs fans is 24:18 In lowest terms it is 4:3

25 We have interviewed 42 Chicago baseball fans. Twenty-four stated they were Sox fans and eighteen stated they were Cubs fans. The ratio of Cubs fans to Sox fans is 18:24

26 We have interviewed 42 Chicago baseball fans. Twenty-four stated they were Sox fans and eighteen stated they were Cubs fans. The ratio of Cubs fans to Sox fans is 18:24 In lowest terms it is 3:4

27 The fraction, 3, can be written 4 as 0.75, but if we are using it as a ratio, we do not write 0.75.

28 The fraction, 4, can be written 3 as, but if we are using it as a ratio, we do not write

29 We often use percents when working with ratios.

30 We often use percents when working with ratios. Percent means hundredths.

31 We often use percents when working with ratios. Percent means hundredths. 42%, then, mean 42 hundredths.

32 We often use percents when working with ratios. Percent means hundredths. 42%, then, mean 42 hundredths

33 We often use percents when working with ratios. Percent means hundredths. 42%, then, mean 42 hundredths = 21 50

34 Rates have some similarities with ratios, but they are not the same.

35 Rates have some similarities with ratios, but they are not the same. Ratios do not contain units.

36 Rates have some similarities with ratios, but they are not the same. Ratios do not contain units. Rates are measures that result from dividing quantities of different units.

37 Here is an example of a rate: 300 miles 6 hours

38 Here is an example of a rate: 300 miles 6 hours = 50 miles 1 hour

39 Here is an example of a rate: 300 miles 6 hours = 50 miles 1 hour 50 mph

40 Here is an example of a rate: 300 miles 5.5 hours

41 Here is an example of a rate: 300 miles 5.5 hours = 600 miles 11 hours

42 Here is an example of a rate: 300 miles 5.5 hours = miles 1 hour

43 Here is an example of a rate: 300 miles 5.5 hours = miles 1 hour about 55 mph

44 Here some commonly used rates: miles per hour (mph)

45 Here some commonly used rates: miles per hour (mph) kilometers per hour (k/h)

46 Here some commonly used rates: miles per hour (mph) kilometers per hour (k/h) feet per second (ft./sec.)

47 Here some commonly used rates: miles per hour (mph) kilometers per hour (k/h) feet per second (ft./sec.) meters per second (m/s)

48 Here some commonly used rates: miles per hour (mph) kilometers per hour (k/h) feet per second (ft./sec.) meters per second (m/s) miles per gallon (mpg)

49 A comparison of two numbers is called a ratio. Rates are measures that result from dividing quantities of different units.