These NCERT Solutions for Class 7 Maths Chapter 2 Fractions and Decimals Ex 2.6 Questions and Answers are prepared by our highly skilled subject experts.
NCERT Solutions for Class 7 Maths Chapter 2 Fractions and Decimals Exercise 2.6
Question 1.
Find:
(i) 0.2 × 6
(ii) 8 × 4.6
(iii) 2.71 × 5
(iv) 20.1 × 4
(v) 0.05 × 7
(vi) 211.02 × 4
(vii) 2 × 0.86
Answer:
(i) 0.2 × 6
Since 2 × 6 = 12 and there is one digit to the right of decimal point in 0.2
∴ 0.2 × 6 = 1.2
(ii) 8 × 4.6
Since 8 × 46 = 368 and there is one digit to the right of decimal point in
∴ 8 × 4.6 = 36.8
(iii) 2.71 × 5
Since 271 × 5 = 1355 and there are two digits to the right of decimal point in 2.71
∴ 2.71 × 5 = 13.55
(iv) 20.1 × 4
Since 201 × 4 = 804 and there is one digit to the right of decimal point in 20.1
∴ 20.1 × 4 = 80.4
(v) 0.05 × 7
Since 5 × 7 = 35 and there are two digits to the right of decimal point
∴ 0.05 × 7 = 0.35
(vi) 211.02 × 4
Since 21102 × 4 = 84408 and there are two digits to the right of the decimal point
∴ 211.02 × 4 = 844.08
(vii) 2 × 0.86
Since 2 × 86 = 172 and there are two digits to the right of the decimal point
∴ 2 × 0.86 = 1.72
Question 2.
Find the area of rectangle whose length is 5.7 cm and breadth is 3 cm.
Answer:
Length of a rectangle = 5.7 cm
Breadth of a rectangle = 3 cm
Area of the rectangle = Length × Breadth
= 5.7 cm × 3 cm = 17.1cm2
Question 3.
Find:
(i) 1.3 × 10
(ii) 36.8 × 10
(iii) 153.7 × 10
(iv) 168.07 × 10
(v) 31.1 × 100
(vi) 156.1 × 100
(vii) 3.62 × 100
(viii) 43.07 × 100
(ix) 0.5 × 10
(x) 0.08 × 10
(xi) 0.9 × 100
(xii) 0.03 × 1000
Answer:
(i) 1.3 × 10 = 13
(ii) 36.8 × 10 = 368
(iii) 153.7 × 10 = 1537
(iv) 168.07 × 10 = 1680.7
(v) 31.1 × 100 = 3110
Note:
(1) If there is one zero, the decimal point is shifted to the right by one place.
(2) If there are two zeroes, the decimal point is shifted to the right by two places.
(vi) 156.1 × 100 = 15610
(vii) 3.62 × 100 = 362
(viii) 43.07 × 100 = 4307
(ix) 0.5 × 10 = 5
(x) 0.08 × 10 = 0.8
(xi) 0.9 × 100 = 90
(xii) 0.03 × 1000 = 30
Question 4.
A two-wheeler covers a distance of 55.3 km in one litre of petrol. How much distance will it cover in 10 litres of petrol?
Answer:
Distance covered in one litre of petrol = 55.3 km
Distance covered in 10 litres of petrol = 55.3 × 10 km = 553 km
Question 5.
Find:
(i) 2.5 × 0.3
(ii) 0.1 × 51.7
(iii) 0.2 × 316.8
(iv) 1.3 × 3.1
(v) 0.5 × 0.05
(vi) 11.2 × 0.15
(vii) 1.07 × 0.02
(viii) 10.05 × 1.05
(ix) 101.01 × 0.01
(x) 100.01 × 1.1
Answer:
(i) 25 × 3 = 75
∴ 2.5 × 0.3 = 0.75
(ii) 1 × 517 = 517
∴ 0.1 × 51.7 = 5.17
(iii) 2 × 3168 = 6336
∴ 0.2 × 316.8 = 63.36
(iv) 13 × 31 = 403
∴ 1.3 × 3.1= 4.03
(v) 5 × 5 = 25
∴ 0.5 × 0.05 = 0.025
(vi) 112 × 15 = 1680
∴ 11.2 × 0.15 = 1.680
(vii) 107 × 2 = 214
∴ 1.07 × 0.02 = 0.0214
(viii) 1005 × 105 = 105525
∴ 10.05 × 1.05 = 10.5525
(ix) 10101 × 1 = 10101
∴ 101.01 × 0.01 = 1.0101
(x) 10001 × 11 = 110011
∴ 100.01 × 1.1 = 110.011