Samacheer Kalvi 7th Maths Solutions Term 2 Chapter 1 Number System Ex 1.4

Tamilnadu Samacheer Kalvi 7th Maths Solutions Term 2 Chapter 1 Number System Ex 1.4

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

Solution:
The unit length between 1 and 2 is divided into 10 equal parts and the third part is taken as Q.
∴ Q represents 1 + 0.3 = 1.3
The unit lenth between 3 and 4 is divided into 10 equal parts and the 6th part is taken as P.
∴ 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 S.
∴ 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.
∴ R represents 6 + 0.8 = 6.8
P(3.6), Q(1.3), R(6.8), 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.
∴ Comparing the digits at tenths place we get 0 < 3.
∴ 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.
∴ 7.01 < 7.3 – Smaller number is 7.01.

(iii) 5.6, 6.05
Comparing the whole number parts, we get 5 < 6.
∴ 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