Page 31 - ICSE Math 8

(c) Which order shows the following rational numbers in ascending order:
26 35 46 17
A = , B = , C = , D =
3 4 5 2
(i) A, B, C, D (ii) B, D, A, C (iii) D, A, B, C (iv) D, C, B, A
(d) The number x and –x are additive inverses. Which number is midway between them on a number
line? 1
(i) 1 (ii) 0 (iii) –1 (iv)
4 2
(e) Which number has the same absolute value as ?
3
8 −8 −4 3
(i) (ii) (iii) (iv)
9 9 3 4
2
(f) The sum of −16 2 + 16 is:
3
3
1 1 1
(i) 32 (ii) 33 (iii) −33 (iv) 0
3 3 3
2. Write True or False.
(a) Irrational numbers are non-terminating numbers.
(b) There exist 10 rational numbers between 1 and 10.
 a c  e a  c e 
(c)  b + d   + f = b +  d − f  is the associative property of addition of rational numbers.



−5 7
(d) is the additive inverse of .
7 5
(e) 1 is the multiplicative identity for multiplication of rational numbers.
3. Fill in the blanks.
(a) The rational number equal to its negative is its _____________.
(b) The product of two rational numbers is always a __________.
(c) The product of a negative and positive rational number is always a __________ number.
(d) Division of rational numbers is ___________ associative.
1
(e) The rational number 3 lies exactly between _________ and _________ on the number line.
2

PRACTICE TIME

−7 16  − 5  −3 3 7 9  −13  13
1. Simplify: (a) + (b) 3 +   (c) + + + +   +
26 39  7  10 −20 15 −10  20  15
2. Verify that x + (y + z) = (x + y) + z.
7 −4 2 3 −13 −7 −2 2
(a) x = , y = , z = (b) x = , y = , z = (c) x = , y = 3, z =
3 5 5 5 15 3 7 3
− 
1 −3 −3  2
3. Subtract the sum of and from the additive inverse of −   .
4 8 8  7 
−8 29
4. From what number should be subtracted to get ?
21 63
p
5. Simplify and write the result in the form q .

 7 5   1 3   4 13   1 1   − 15 7   1 
(a)  2 × 3  +  6 × 2   −   3 × 8  (b)  4 × 2   +   7 × − 18   −   2 × 4 






19