184 MATHEMATICS
- Which is greater in each of the following:
(i)(^25) ,
32 (ii)
(^54) ,
63 (iii)
(^32) ,
43
(iv)
(^11) ,
44 (v)
3,3^24
75
- Write the following rational numbers in ascending order:
(i)(^321) ,,
555 (ii)
- 12 4,,
39 3 (iii)
(^333) ,,
724
9.9 OPERATIONS ON RATIONAL NUMBERS
You know how to add, subtract, multiply and divide integers as well as fractions. Let us
now study these basic operations on rational numbers.
9.9.1 Addition
Let us add two rational numbers with same denominators, say^75 and
33
.
We find
75
33
+⎛⎞
⎜⎟⎝⎠
On the number line, we have:
The distance between two consecutive points is
1
3. So adding
5
3
to
7
3 will
mean, moving to the left of^7
3
, making 5 jumps. Where do we reach? We reach at
2
3.
So,
752
33 3
+⎛⎞
⎜⎟⎝⎠.
Let us now try this way:
72 ()57 5()
33 3 3
We get the same answer.
Find
63 ()^25 ()
,
55 77
++ in both ways and check if you get the same answers.
3
3
2
3
1
3
0
3
1
3
2
3
3
3
4
3
5
3
6
3
7
3
8
3