1. A. Rational Numbers Math 9

2. Outcomes  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

3. Big Ideas  Rational numbers are fractions! Most real life measurements use fractions/decimals!

4. Key Ideas

5. 1. What is a Rational Number?  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

6. 1. What is a Rational Number?

15.  When in decimal form how you can tell if a number is rational is if the decimal terminates or repeats.  Ex. 2.25 Terminates  Ex. 2.333333333333….. Or 4.6

16.  When looking at a decimal if the decimal does not repeat or terminate then it is irrational.  Ex. 2.34567534789064567555346623453345433  Ex. 5.45456456745678456789

17. Example 1

18. Example 2

19. Example 3

20. Example 4

21. Practice  Ex. 3.1 (p.100)  #1-8,10,11,12 oie, 13, 14 oie, 16-18 oie, 21, 22, 23-24 oie  Or  #3-8,10,11,12 oie, 13, 14 oie, 16-18 oie, 21, 22, 23-25 oie, 26, 27

22. 2. Adding Rational Numbers  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

24.  Remember that you only add the numerators and the denominators stay the same.

25. Example 1

27.  To ADD decimals:  Line up the decimal points and add the columns from right to left.  Place a decimal point in the answer directly below the other decimal points.

29. Example 2

30. Example 3

31. Practice  Ex. 3.2 (p.111)  #1-15 oie, 17,18  Or  #3,4,7, 9-11 oie, 12-22

32. 3. Subtracting Rational Numbers  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

34.  Remember just like adding rational numbers you need a common denominator and you only subtract the numerators and the denominators stay the same.

35. Example 1

36.  To Subtract:  Line up the decimal points.  Subtract the columns from right to left, regrouping if necessary.  Place a decimal point in the answer directly below the other decimal points.

39. Example 2

40. Example 3

41. Practice  Ex. 3.3 (p.119)  #1-14 oie  Or  #4-17 oie

42. 4. Multiplying Rational Numbers  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

47. Example 1

48. Example 2

49. Example 3

50. Practice  Ex. 3.4 (p.127)  #1-14  Or  #5-18

51. 5. Dividing Rational Numbers  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

53.  In order to divide rational numbers we have to take the reciprocal of the divisor then multiply instead of divide.

54. Example 1

55.  To divide decimals we can use long division just like to we would if we had integers.  We just have to remember to put the decimal in the place of the dividend.

56. Example 2

57. Example 3

58. Practice  Ex. 3.5 (p.134)  #1-13, 17,18  Or  #6-21

59. 6. Order of Operations with Rationals  N9.2 N9.2  Demonstrate understanding of rational numbers including:  comparing and ordering  relating to other types of numbers  solving situational questions.

61.  BEDMAS 1.Brackets 2.Exponents 3.Division and multiplication (work left to right) 4.Adding and Subtracting (work left to right)

62. Example 1

64. Example 2

65. Example 3

66. Practice  Ex. 3.6 (p.140)  #1-17 oie  Or  #6-21 oie