Exercise 1.5 - Chapter 1 Numbers Term 1 6th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024]

Ex 1.5
Question 1 .

Fill in the blanks.
(i) The difference between the smallest natural number and the smallest whole number is
(ii) $17 \times=34 \times 17$
(iii) When is added to a number, it remains the same.
(iv) Division by is not defined.
(v) Multiplication by leaves a number unchanged.
Solution:
(i) 1
Hint: $1-0=1$
(ii) 34
(iii) 0
(iv) 0
(v) 1

Question 2 .
Say True or False.
1. 0 is the identity for multiplication of whole numbers.
2. Sum of two whole numbers is always less than their product.
3. Both addition and multiplication are associative for whole numbers.
4. Both addition and multiplication are commutative for whole numbers.
5. Multiplication is distributive over addition for whole numbers.
Solution:
1. False
2. False
3. True
4. True
5. True

Question $3 .$
Name the property being illustrated in each of the cases given below:
1. $75+34=34+75$ 2. $(12 \times 4) \times 8=12 \times(4 \times 8)$ 3. $50+0=50$ 4. $50 \times 1=50$ 5. $50 \times 42=50 \times 40+50 \times 2$
Solution:
2. Multiplication is associative
$3.0$ is the additive identity
4. 1 is the multiplicative identity.
5. Distributivity of multiplication over addition

Question $4 .$
Use the properties of whole numbers and simplify.
(i) $50 \times 102$
(ii) $500 \times 689-500 \times 89$
(iii) $4 \times 132 \times 25$
(iv) $196+34+104$
Solution:

\begin{aligned} &\text { (i) } 50 \times 102 \\ &=50 \times(100+2) \\ &=(50 \times 100)+(50 \times 2) \\ &=5000+100=5100 \end{aligned}
(ii) $500 \times 689-500 \times 89$
\begin{aligned} &=500 \times(689-89) \\ &=344500-44500 \\ &=300000 \\ &=500 \times(689-89) \\ &=500 \times 600 \\ &=3,00000 \end{aligned}

\text { (iii) } \begin{aligned} &(4 \times 132) \times 25 \\ =& 4 \times(132 \times 25) \\ =&(4 \times 132) \times 25 \\ =& 528 \times 25 \\ =& 13200 \\ =& 4 \times(132 \times 25) \\ =& 4 \times 3300 \\ =& 13200 \end{aligned}
\begin{aligned} &\text { (iv) }(196+34)+104=196+(34+104) \\ &(196+34)+104=230+104=334 \\ &196+(34+104)=196+138=334 \end{aligned}

Objective Type Questions
Question $5 .$

$(53+49) \times 0$ is
(a) 102
(b) 0
(c) 1
(d) $53+49+0$
Solution:
(b) 0

$53 \times 0+49 \times 0=0+0=0$

Question $6 .$
$\frac{59}{1}$ is
(a) 1
(b) 0
(c) $\frac{1}{59}$
(d) 59
Solution:
(d) 59

Question $7 .$
The product of a non-zero whole number and its successor is always
(a) an even number
(b) an odd number
(c) zero
(d) none of these
Solution:
(a) an even number

Question $8 .$
The whole number that does not have a predecessor is
(a) 10
(b) 0
(c) 1
(d) none of these
Solution:
(b) 0
0 is the smallest whole number

Question $9 .$
Which of the following expressions is not zero?
(a) $0 \times 0$
(b) $0+0$
(c) $2 / 0$
(d) $0 / 2$
Solution:
(c) $2 / 0$

Question 10 .
Which of the following is not true?
(a) $(4237+5498)+3439=4237+(5498+3439)$
(b) $(4237 \times 5498) \times 3439=4237 \times(5498 \times 3439)$
(c) $4237+5498 \times 3439=(4237+5498) \times 3439$
(d) $4237 \times(5498+3439)=(4237 \times 5498)+(4237 \times 3439)$
Solution:
(c) $4237+5498 \times 3439=(4237+5498) \times 3439$