Page 66 - ICSE Math 7

(c) State which of these is a rational number?
5
(i) π (ii) (iii) √ 2 (iv) 1.7
0
3
(d) The product of rational number and its multiplicative inverse is ___________.
4
(i) 1 (ii) 0 (iii) 3 (iv) 9
4 16

5
7
(e) Without actual computation, we can say that the value of 5 ÷ 7 is ___________.
9 9
(i) greater than 1 (ii) greater than 2 (iii) less than 1 (iv) less than 1
2
2. Write True or False.
(a) Reciprocal of 0 does not exist.
(b) The integer zero is not a rational number.

(c) Two rational numbers having different numerators and different denominators can never be
equal.
(d) The number 1 is an identity element for division of rational numbers.
(e) Every terminating decimal represents a rational number but every rational number is not
necessarily represented by a terminating decimal.
(f) Every irrational number is represented by a non-terminating repeating decimal.

3. Fill in the blanks.
p
(a) A rational number is said to be in _____________ form if p and q have no common factor
q
other than 1.
a c
(b) Two fractions and are equal, iff, ad equals _____________.
b d
a c
(c) If a, b and c are integers and b > 0, then < iff a _______ c.
b b
(d) All rational numbers are either _____________ decimals or non-terminating recurring.
(e) An example of a number that is rational, integer, whole but not natural is _____________.

PRACTICE TIME

1. Identify the positive and negative rational numbers.

3 –8 –17 , 3 , – –6
,
,
4 9 –21 –8 10
2. Multiply. (a) 6 × –4 (b) 13 × 21 (c) 5 × 11 (d) –11 × –4
11 7 19 17 9 45 18 77

3. Divide. (a) 2 ÷ 5 (b) –3 ÷ 4 (c) –4 ÷ 12 (d) –1 2 ÷ 21
3 9 5 15 5 15 5 30
–6
4. Express as a rational number with:
10
(a) numerator 18 (b) denominator 5 (c) numerator –12

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