it is a ppt on rational numbers for class 8th which is very attractive.

1. 2.2 Rational Numbers
 Objectives:
1. To show that a number is a rational #
2. To graph rational #’s
3. To compare rational #’s using < or >

2. Classes of Numbers

3. Rational Numbers
 Comes from the word “ratio”
 Any number that can be
expressed as the ratio of two
integers is a fraction
 A fraction is a rational number

4. Turn any whole # into a fraction
by….
Putting it over 1

5. Ex 1: Write as the ratio of two
integers
3
1
−
3−

6. Ex 2: Write as a ratio of two
integers:
7
etcor
2
14
1
7

7. Any terminating or repeating decimal
can be written as a fraction
It there is
 1 decimal place …. put the number over
10
 2 decimal places … put over 100
 3 decimal places … put over 1000
****Remember to REDUCE*******

8. Ex 3: Write as the ratio of two
integers
92
10
=
9.2

9. Ex 4: Write as a ratio of two
integers:
0.7
10
7

10. Ex 5: Write as a ratio of two
integers:
4.5
2
9
10
45
or

11. Ex 6: Write the following number
as a ratio of two integers:
-9.23
923
100
−

12. Write a mixed number as a ratio
of two integers by…
Turning it into an improper fraction

13. Ex 7: Write 7 ½ as a ratio of two
integers
15
2

14. Negative
Rational Numbers
“Negative three-fourths”
4
3
−
4
3−
4
3
−

15. Graphing Fractions on the # line
 Turn improper fractions to mix numbers
 Find the 2 whole numbers the fraction is
in between and put a dot between those
two whole numbers

16. Ex 8: Graph on the Number Line
0 42-6 -4 -2 6
2
5

17. Ex 9: Graph on the Number Line
0 42-6 -4 -2 6
5.4−

18. Comparing Decimals
 Compare each place value

19. Ex 10: Comparing Rational
Numbers
Using “< “ and “>”
1.38  1.83<

20. Ex 11: Comparing Rational
Numbers
Using “< “ and “>”
>545.0 543.0

21. Comparing Fractions
 If they have the same denominator
compare numerators
 If they have different denominators use
the heart method

22. Heart Method
 Cross multiply and bring product down
 Compare the product using < or >

23. Ex 12: Comparing Rational
Numbers
Using “< “ and “>”

4
3
8
5
Cross multiply and compare
their products

24. Ex 13: Compare Using < or >
2
3
− 4
5
−

25. Ex 14: Write the rational orders
from least to greatest
2 1 3 5 3 1
, , , , ,
3 2 4 6 8 6
− − −

26. Density Property
 Between any two rational numbers there
is another rational number

27. Ex 15: Find a number between
1 2
3 3
and

28. Ex 16: Find a number in
between
0.45 and 0.46

29. Assignment:
Page 61 (2-38) even

30. 0 42-6 -4 -2 6