Samacheer Kalvi 7th Maths Solutions Term 3 Chapter 1 Number System Ex 1.3
Samacheer Kalvi 7th Maths Solutions Term 3 Chapter 1 Number System Ex 1.3
Tamilnadu Samacheer Kalvi 7th Maths Solutions Term 3 Chapter 1 Number System Ex 1.3
Question 1.
Find the product of the following
(i) 0.5 × 3
(ii) 3.75 × 6
(iii) 50.2 × 4
(iv) 0.03 × 9
(v) 453.03 × 7
(vi) 4 × 0.7
Solution:
(i) 0.5 × 3
5 × 3 = 15
∴ 0.5 × 3 = 1.5
(ii) 3.75 × 6
375 × 6 = 2250
3.75 × 6 = 22.50
(iii) 50.2 × 4
502 × 4 = 2008
50.2 × 4 = 200.8
(iv) 0.03 × 9
3 × 9 = 27
0.03 × 9 = 0.27
(v) 453.03 × 7
45303 × 7 = 317121
453.03 × 7 = 3171.21
(vi) 4 × 0.7
4 × 7 = 28
4 × 0.7 = 2.8
Question 2.
Find the area of the parallelogram whose base is 6.8 cm and height is 3.5 cm.
Solution:
Base of the parallelogram b = 6.8 cm
Height of the parallelogram h = 3.5 cm
Area of the parallelogram A = b × h sq.units = 6.8 × 3.5 cm2
Area of the parallelogram = 23.80 cm2
Question 3.
Find the area of the rectangle whose length is 23.7 cm and breadth is 15.2 cm.
Solution:
Length of the rectangle l = 23.7 cm
Breadth of the rectangle b= 15.2 cm
Area of the rectangle A = l × b sq.units
= 23.7 × 15.2 cm2
Area of the rectangle = 360.24 cm2
Question 4.
Multiply the following
- 2.57 × 10
- 0.51 × 10
- 125.367 × 100
- 34.51 × 100
- 62.735 × 100
- 0.7 × 10
- 0.03 × 100
- 0.4 × 1000
Solution:
- 2.57 × 10 = 25.7
- 0.51 × 10 = 5.1
- 125.367 × 100 = 12536.7
- 34.51 × 100 = 3451
- 62.735 × 100 = 6273.5
- 0.7 × 10 = 7.0
- 0.03 × 100 = 3
- 0.4 × 1000 = 400
Question 5.
A wheel of a baby cycle covers 49.7 cm in one rotation. Find the distance covered in 10 rotations.
Solution:
Length covered in 1 rotation = 49.7 cm
Length covered in 10 rotations = 49.7 × 10 cm = 497 cm
Question 6.
A picture chart costs ₹ 1.50. Radha wants to buy 20 charts to make an album. How much does she have to pay?
Solution:
Cost of 1 chart = ₹ 1.50
Cost of 20 charts = ₹ 1.50 × 20 = ₹ 30.00
Cost of 20 charts = ₹ 30
Question 7.
Find the product of the following.
(i) 3.6 × 0.3
(ii) 52.3 × 0.1
(iii) 537.4 × 0.2
(iv) 0.6 × 0.06
(v) 62.2 × 0.23
(vi) 1.02 × 0.05
(vii) 10.05 × 1.05
(viii) 101.01 × 0.01
(ix) 100.01 × 1.1
Solution:
(i) 3.6 × 0.3
36 × 3 = 108
3.6 × 0.3 = 1.08
(ii) 52.3 × 0.1
523 × 1 = 523
52.3 × 0.1 = 5.23
(iii) 537.4 × 0.2
5374 × 2 = 10748
537.4 × 0.2 = 107.48
(iv) 0.6 × 0.06
6 × 6 = 36
0.6 × 0.06 = 0.036
(v) 62.2 × 0.23
622 × 23 = 14306
62.2 × 0.23 = 14.306
(vi) 1.02 × 0.05
102 × 5 = 510
1.02 × 0.05 = 0.0510
(vii) 10.05 × 1.05
1005 × 105 = 105525
10.05 × 1.05 = 10.5525
(viii) 101.01 × 0.01
10101 × 1 = 10101
101.01 × 0.01 = 1.0101
(ix) 100.01 × 1.1
1001 × 11 = 110011
100.01 × 1.1 = 110.011
Objective Type Questions
Question 1.
1.07 × 0.1 _______
(i) 1.070
(ii) 0.107
(iii) 10.70
(iv) 11.07
Answer:
(ii) 0.107
Hint:
107 × 1 = 107
1.07 × 0.1 = 0.107
Question 2.
2.08 × 10 = ______
(i) 20.8
(ii) 208.0
(iii) 0.208
(iv) 280.0
Answer:
(i) 20.8
Hint:
208 × 10 = 2080
2.08 × 10 = 20.80 = 20.8
Question 3.
A frog jumps 5.3 cm in one jump. The distance travelled by the frog in 10 jumps is _______
(i) 0.53 cm
(ii) 530 cm
(iii) 53.0 cm
(iv) 53.5 cm
Answer:
(iii) 53.0 cm
Hint:
53 × 10 = 530
5.3 × 10 = 53.0