Exercise 1.4 - Chapter 1 Number Systems Term 2 7th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated By SaraNextGen

On April 24, 2024, 11:35 AM

Ex $1.4$
Question $1 .$
Write the decimal numbers represented by the points $P, Q, R$ and $S$ on the given number line.

The unit length between 1 and 2 is divided into 10 equal parts and the third part is taken as $Q$. $\therefore$ Q represents $1+0.3=1.3$
The unit lenth between 3 and 4 is divided into 10 equal parts and the 6 th part is taken as P. $\therefore$ P represents $3+0.6=3.6$
The unit length between 4 and 5 is divied into 10 equal parts and the second part is taken as $\mathrm{S}$. $\therefore \mathrm{S}$ represents $4+0.2=4.2$
The unit length between 6 and 7 is divided into 10 equal parts and the 8th part is taken. $\therefore \mathrm{R}$ represents $6+0.8=6.8$
$\mathrm{P}(3.6), \mathrm{Q}(1.3), \mathrm{R}(6.8), \mathrm{S}(4.2)$

Question $2 .$
Represent the following decimal numbers on the number line.
(i) $1.7$
(ii) $0.3$
(iii) $2.1$
Solution:
(i) $1.7$
We know that $1.7$ is more than 1 , but less than 2 .

There are one ones and 7 tenths in it. Divide the unit length between 1 and 2 on the number line into 10 equal parts and take 7 parts which represents $1.7=1+0.7$

(ii) $0.3$
We know that $0.3$ is more than 0 , but less than 1 .
There are 3 tenths in it. Divide the unit lenght between 0 and 1 on the number line into 10 equal parts and take 3 parts, which represent $0.3$.

(iii) $2.1$
We knowthat $2.1$ is more than 2 and less than $3 .$
There are 2 ones and 1 tenths in it.
Divide the unit length between 2 and 3 into 10 equal parts and take 1 part, which represemt $2.1=2$ $+0.1$

Question $3 .$
Between which two whole numbers, the following decimal numbers lie?
(i) $3.3$
(ii) $2.5$
(iii) $0.9$
Solution:
(i) $3.3-3.3$ lies between 3 and 4 .
(ii) $2.5-2.5$ lies between 2 and 3 .
(iii) $0.9-0.9$ lies between 0 and 1 .

Question $4 .$
Find the greater decimal number in the following.
(i) $2.3,3.2$
(ii) $5.6,6.5$
(iii) $1.2,2.1$
Solution:
(i) $2.3,3.2$
Comparing the whole number parts of $2.3$ and $3.2$ we get $3>2$.
$3.2>2.3$ - Greater number is $3.2$
(ii) $5.6,6.5$
Comparing the whole number parts of $5.6$ and $6.5$, we get $6>5$.
$6.5>5.6$ - Greater number is $6.5$

(iii) $1.2,2.1$
Comparing the whole number parts of $1.2$ and $2.1$, we get $2>1$. $2.1>1.2$ - Greater number is $2.1$
 

Question 5 .
Find the smaller decimal number in the following.
(i) $25.3,25.03$
(ii) $7.01,7.3$
(iii) $5.6,6.05$
Solution:
(i) $25.3,25.03$
The whole number parts of both the numbers are equal.
$\therefore$ Comparing the digits at tenths place we get $0<3$.
$\therefore 25.03<25.3$ - Smaller number $25.03$
(ii) $7.01,7.3$
The whole number parts of both the numbers are equal.
Comparing the digits at tenths place we get $0<3$.
$\therefore 7.01<7.3$ - Smaller number is $7.01$.
(iii) $5.6,6.05$
Comparing the whole number parts, we get $5<6$.
$\therefore 5.6<6.05-$ Smaller number is $5.6$
 

Objective Question

Question $6 .$
Between which two whole numbers $1.7$ lie?
(i) 2 and 3
(ii) 3 and 4
(iii) 1 and 2
Answer:
(iii) 1 and 2

Question $7 .$
The decimal number which lies between 4 and 5 is
(i) $4.5$
(ii) $2.9$
(iii) $1.9$
Answer:
(i) $4.5$