Page 15 - Maths Skills - 8

Rational Numbers 13

− −1 5 3 7 6 6 8 2 5
(iii) , ,,, (iv) ,, ,
2 3 4 2 − 5 7 9 4 9
3. Arrange the following in descending order.
1 − 6 − 13 18 19
7 −16 −15 63
,
(i) − 3, , , , (ii) 5 − , , ,
13 39 26 65 10 15 25 60
2 5 − 3 1 − 3 9 8 - 15 23
(iii) , , ,, (iv) ,, ,
5 − 6 7 9 − 5 3 6 26 39
4. Are the following pairs of rational numbers positive or negative?

19 16 − − 7 14 73 − 19 − 9 12
(i) and (ii) and (iii) − and (iv) and
37 111 15 30 108 36 −105 140

5. Express −172 as a rational number
204
(i) with numerator 43 (ii) with denominator – 612

− − 7 15
6. Represent and on the same number line and find which is greater.
5 7
7. Find the value of x in each of the following.

x 3 19 57
15 6 30
(i) 3 (ii) (iii) x (iv) =
x 25 5 105 7 x
8. Write the following in standard form.

2 − 399 − 72 5670
(i) 8 (ii) (iii) (iv)
17 603 −150 10395

Challenge

Instructions: This task may be performed in the classroom. Teacher may ask questions in groups and
observe the level of understanding.

Look into the given table and say whether the following statements are true or false. Given reasons for your
answer with examples.

(a) Every integer is a rational number.
(b) Every rational number is an irrational number.

(c) Every rational number is a whole number.
(d) Every integer is a natural number.
(e) Every natural number is an integer.

(f) Every natural number is a whole number.
(g) Every whole number is a natural number.

OPERATIONS ON RATIONAL NUMBERS
Let us start with operations of addition followed by subtraction, multiplication and division.