Decimal Fractions ICSE Class-7th Concise Selina Maths Solutions Chapter-4. We provide step by step Solutions of Exercise / lesson-4 Decimal Fractions for ICSE Class-7 Concise Selina Mathematics. Our Solutions contain all type Questions with Exe-4 A, Exe-4 B, Exe-4 C Exe-4 D , Exe-4 E and  Exe-4 F to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-7.

## Decimal Fractions ICSE Class-7th Concise Selina Maths Solutions Chapter-4

–: Select Topics :–

Exe-4 A,

Exe-4 B,

Exe-4 C,

Exe-4 D,

Exe-4 E,

Exe-4 F,

### Exercise – 4 A

Decimal Fractions ICSE Class-7th Concise Selina

#### Question-1:-

Convert the following into fractions in their lowest terms :
(i) 3.75
(ii) 0.5
(iii) 2.04
(iv) 0.65
(v) 2.405
(vi) 0.085
(vii) 8.025

(i) 3.75

(ii) 0.5

​ =  5/10 =1/2

(iii) 2.04

(HCF of 204 and 100 = 4)

= 51/25

(iv) 0.65

(v) 2.405

(vi) 0.085

= 17/200

(vii) 8.025

=  321/40​

#### Question-2:-

Convert into decimal fractions (i)

=   14/5

=  2.8

(ii)

= 0.79

(iii)

=  0.0037

(iv)

7543/10000

=  0.7543

(v)

=  0.75

(vi)

=  48/5

=  9.6

(vii)

= 5.875

(viii)

= 5.875

#### Question-3:-

Write the number of decimal places in :
(i) 0.4762
(ii) 7.00349
(iii) 8235.403
(iv) 35.4
(v) 2.608
(vi) 0.000879

(i) Four

(ii) five

(iii) three

(iv) one

(v) three

(vi) six

Question-4:-

Write the following decimals as word statements :
(i) 0.4,0.9,0.1
(ii) 1.9, 4.4, 7.5
(iii) 0.02, 0.56, 13.06
(iv) 0.005,0.207, 111.519
(v) 0.8, 0.08, 0.008, 0.0008
(vi)256.1, 10.22, 0.634

(i) 0.4 – zero point four

0.9 – zero point nine

0.1 – zero point one

(ii) 1.9 – one point nine

4.4 – four point four

7.5 – seven point five

(iii) 0.02 – zero point zero two

0.56 – zero point five six

13.06 – thirteen point zero six

(iv) 0.005 – zero point zero zero five

0.207 – zero point two zero seven

111.519 – one hundred eleven point five one nine

(v) 0.8 – zero point eight

0.08 – zero point zero zero eight

0.008 – zero point zero zero zero eight

0.0008 – zero point zero zero zero zero eight

(vi) 256.1 – two hundred fifty six point one

10.22 – ten point two two

0.634 – zero point six three four

#### Question-5:-

Convert the given fractions into like fractions:
(i) 0.5,3.62,43.987 and 232.0037
(ii) 215.78, 33.0006, 530.3 and 0.03569

(i) 0.5000

3.6200

43.9870

232.0037

(ii) 215.78000

33.00060

530.30000

0.03569

### Exercise  – 4 B

Selina solutions Decimal Fractions for ICSE Class-7th

#### Question-1:-

(i) 0.5 and 0.37

(ii) 3.8 and 8.7
(iii) 0.02, 0.008 and 0.309
(iv) 0. 4136, 0. 3195 and 0.52
(v) 9.25, 3.4 and 6.666
(vi) 3.007, 0.587 and 18.341
(vii) 0.2, 0.02 and 2.0002
(viii) 6. 08, 60.8, 0.608 and 0.0608
(ix) 29.03, 0.0003, 0.3 and 7.2
(x) 3.4, 2.025, 9.36 and 3.6221

(i) 0.5 and 0.37

= 0.5 + 0.37 = 0.87

(ii) 3.8 and 8.7

= 3.8 + 8.7 = 12.5

(iii) 0.02, 0.008 and 0.309

= 0.02 + 0.008 + 0.309 = 0.337

(iv) 0. 4136, 0. 3195 and 0.52

= 0. 4136 + 0. 3195 + 0.52 = 1.2531

(v) 9.25, 3.4 and 6.666

= 9.25 + 3.4 + 6.666 = 19.316

(vi) 3.007, 0.587 and 18.341

= 3.007 +  0.587 + 18.341 = 21.935

(vii) 0.2, 0.02 and 2.0002

= 0.2 + 0.02 + 2.0002 = 2.2202

(viii) 6. 08, 60.8, 0.608 and 0.0608

= 6.08 + 60.8 + 0.608 + 0.0608 = 67.5488

(ix) 29.03, 0.0003, 0.3 and 7.2

= 29.03 + 0.0003 + 0.3 + 7.2 = 36.5303

(x) 3.4, 2.025, 9.36 and 3.6221

= 3.4 + 2.025 + 9.36 + 3.6221 = 18.4071

#### Question-2:-

Subtract the first! number from the second :
(i) 5.4, 9.8
(ii) 0.16, 4.3
(iii) 0.82, 8.6
(v) 2.237, 9.425
(vi) 41 .03, 59.46
(vii) 3.92. 26.86
(viii) 4.73, 8.5
(ix) 12.63, 36.2
(x) 0.845, 3.71

(i) 5.4, 9.8

4.30 – 0.16

= 4.14

(ii) 0.16, 4.3

4.30 – 0.16

= 4.14

(iii) 0.82, 8.6

8.60 – 0.82

= 7.78

(iv)  0.07, 8.43

8.43 – 0.07

= 8.36

(v) 2.237, 9.425

9.425 – 2.237

= 7.188

(vi) 41 .03, 59.46

59.46 – 41.03

= 18.43

(vii) 3.92. 26.86

26.86 – 3.92

= 22.94

(viii) 4.73, 8.5

8.50 – 4.73

= 3.77

(ix) 12.63, 36.2

36.20 – 12.63

= 23.57

(x) 0.845, 3.71

3.710 – 0.845

= 2.865

#### Question-3:-

Simplify :
(i) 28.796 -13.42 – 2.555
(ii) 93.354 – 62.82 – 13.045
(iii) 36 – 18.59 – 3.2
(iv) 86 + 16.95 – 3.0042
(v) 32.8 – 13 – 10.725 +3.517
(vi) 4000 – 30.51 – 753.101 – 69.43
(vii) 0.1835 + 163.2005 – 25.9 – 100
(viii) 38.00 – 30 + 200.200 – 0.230
(ix) 555.555 + 55.555 – 5.55 – 0.555

(i) 28.796 -13.42 – 2.555

= 28.796 – (13.42 – 2.555)

= 28.796 – 15.975

= 12.821

(ii) 93.354 – 62.82 – 13.045

= 28.796 – (13.42 – 2.555)

= 28.796 – 15.975

= 12.821

(iii) 36 – 18.59 – 3.2

= 36 – (18.59 + 3.2)

= 36 – (21.79)

= 14.21

(iv) 86 + 16.95 – 3.0042

=  86.00 + 16.95

= 102.95 – 3.0042

= 99.9458

(v) 32.8 – 13 – 10.725 +3.517

= (32.8 + 3.517) – (13 + 10.725)

= 36.317 – 23.725

= 12.592

(vi) 4000 – 30.51 – 753.101 – 69.43

= 4000 – (30.51 + 753.101 + 69.43)

= 4000 – 853.041

= 3146.959

(vii) 0.1835 + 163.2005 – 25.9 – 100

= (0.1835 + 163.2005) – (25.9 + 100)

= 163.3840 – 125.9

= 37.484

(viii) 38.00 – 30 + 200.200 – 0.230

= (38.00 + 200.200) – (30 + 0.230)

= 238.200 – 30.230

= 207.970

= 207.97

(ix) 555.555 + 55.555 – 5.55 – 0.555

= (555.555 + 55.555) – (5.55 + 0.555)

#### Question-4:-

Find the difference between 6.85 and 0.685.

= 6.85 – 0.685

= 6.165

#### Question-5:-

Take out the sum of 19.38 and 56.025 then subtract it from 200. 111.

Sum of 19.38 + 56.025

= 75.405

Difference of 200.111 and 75.405

= 200.111 – 75.405

= 124.706

#### Question-6:-

Add 13.95 and 1.003 ; and from the result, subtract the sum of 2.794 and 6.2.

Sum of 13.95 and 1.003

= 13.95 + 1.003

= 14.953

Sum of 2.794 and 6.2

= 2.794 + 6.2

= 8.994

Difference of 14.953 and 8.994

= 14.953 – 8.994

= 5.959

#### Question-7:-

What should be added to 39.587 to give 80.375 ?

Sum = 80.375

Given number = 39.589

∴ The number which is to be added

= 80.375 – 39.587

= 40.788

#### Question-8:-

What should be subtracted from 100 to give 19.29?

Sum = 100

The number = 19.29

∴ The number which is to be subtracted

= 100 – 19.29

= 80.71

#### Question-9:-

What is the excess of 584.29 over 213.95 ?

Total = 584.29

Given number = 213.95

Required difference = 584.29 – 213.95

= 370.34

#### Question-10:-

Evaluate:
(i) (5.4 – 0.8) + (2.97 -1.462)
(ii) (6.25 + 0.36) -(17.2 – 8.97)
(iii) 9.004 + (3 -2.462)
(iv) 879.4 – (87.94 – 8 .794)

(i)

(5.4 – 0.8) + (2.97 -1.462)

= 4.6 + 1.508

= 6.108

(ii)

(6.25 + 0.36) -(17.2 – 8.97)

= 6.61 – 8.23

= – 1.62

(iii)

9.001 + (3 – 2.462)

= 9.004 + 0.538

= 9.542

(iv)

879.4 – (87.94 – 8 .794)

= 879.4 – 79.146

= 800.254

#### Question-11:-

What is the excess of 75 over 48.29?

Excess of 75 over 48.29

75.00
– 48.29
26.71

∴ Excess of 75 over 48.29 is 26.71

#### Question 12.

If A = 237.98 and B = 83.47.
Find :
(i) A – B
(ii) B – A.

(i) A – B

A = 237.98

B = 83.47

A – B = 237.98 – 83.47

= 154.51

(ii) B – A

= 83.47 – 237.98

= – 154.51

#### Question-13:-

The cost of one kg of sugar increases from ?28.47 to T32.65. Find the increase in cost.

Initial cost of sugar = ₹ 28.47

Increase cost of sugar = ₹ 32.65

∴ Increase of sugar in cost = ₹ 5.18

Exercise – 4 C

### Decimal Fractions ICSE Class-7th Mathematics

#### Question-1:-

Multiply:
(i) 0.87 by 10
(ii) 2.948 by 100
(iii) 6.4 by 1000
(iv) 5.8 by 4
(v) 16.32 by 28
(vi) 5. 037 by 8
(vii) 4.6 by 2.1
(viii) 0.568 by 6.4

(i) 0.87 by 10

= 0.87 × 10 = 8.7

(ii) 2.948 by 100

= 2.948 × 100 = 294.8

(iii) 6.4 by 1000

= 6.4 × 1000 = 6400

(iv) 5.8 by 4

= 5.8 × 4 = 23.2

(v) 16.32 by 28

= 16.32 × 28 = 456.96

(vi) 5. 037 by 8

= 5.037 × 8 = 40.296

(vi) 4.6 by 2.1

= 4.6 × 2.1 = 9.66

(viii) 0.568 by 6.4

= 0.568 × 6.4 = 3.6352

#### Question-2:-

Multiply each number by 10, 100, 1000 :
(i) 0.5
(ii) 0.112
(iii) 4.8
(iv) 0.0359
(v) 16.27
(vi) 234.8

(i)

0.5 x 10 = 5,

0.5 x 100 = 50,

0.5 x 1000 = 500

(ii)

0.112 x 10= 1.12,

0.112 x 100 = 11.2,

0.112 x 1000= 112

(iii)

4.8 x 10 = 48,

4.8 x 100 = 480,

4.8 x 1000 = 4800

(iv)

0.0359 x 10 = 0.359,

0.0359 x 100 = 3.59,

0.0359 x 1000 = 35.9

(v)

16.27 x 10 = 162.7,

16.27 x 100 = 1627,

16.27 x 1000= 16270

(vi)

234.8 x 10 = 2348,

234.8 x 100 = 23480,

234.8 x 1000 = 234800

#### Question-3:-

Evaluate:
(i) 5.897 x 2.3
(ii) 0.894 x 87
(iii) 0.01 x 0.001
(iv) 0.84 x 2.2 x 4
(v) 4.75 x 0.08 x 3
(vi) 2.4 x 3.5 x 4.8
(vii) 0.8 x 1.2 x 0.25
(viii) 0.3 x 0.03 x 0.003
(ix) 12.003 x (0.2)5

(i)

5.897 × 2.3

= 13.5631

(ii)

0.894 × 87

= 77.778

(iii)

0.01 × 0.001

= 0.00001

(iv)

0.84 × 2.2 × 4 = 0.84

=0.84 × 8.8

= 7.392

(v)

4.75 × 0.08 × 3 = 4.75 × 0.08 × 3

= 4.75 × 0.24

= 1.1400

= 1.14

(vi)

2.4 × 3.5 × 4.8 = 8.40 × 4.8

= 8.4 × 4.8

= 40.32

(vii)

0.8 × 1.2 × 0.25 = 0.96 × 0.25

= 0.2400

= 0.24

(viii)

0.3 × 0.03 × 0.003 = 0.009 × 0.003

= 0.000027

= 0.24

(ix)

12.003 × (0.2)5

= 12.003 × 0.2 × 0.2 × 0.2 × 0.2 × 0.2

= 12.003 × 0.00032 = 0.00384096

#### Question-4:-

Divide :
(i) 54.9 by 10
(ii) 7.8 by 100
(iii) 324.76 by 1000
(iv) 12.8 by 4
(v) 27.918 by 9
(vi) 4.672 by 8
(vii) 4.32 by 1.2
(viii) 7.644 by 1.4
(ix) 4.8432 by 0.08

(i)

= 54.9 ÷ 10

= 5.49

(ii)

= 7.8 ÷ 100

= 0.078

(iii)

= 324.76 ÷ 1000

= 0.32476

(iv)

= 12.8 ÷ 4

= 3.2

(v)

= 27.918 ÷ 9

= 3.102

(vi)

= 4.672 ÷ 8

= 0.584

(vii)

= 4.32 ÷ 1.20

= 432 ÷ 120

= 3.6

(viii)

= 7.644 ÷ 1.400

= 7644 ÷ 1400

= 5.46

(ix)

= 4.8432 ÷ 0.0800

= 48432 ÷ 800

= 60.54

#### Question-5:-

Divide each of the given numbers by 10, 100, 1000 and 10000
(i) 2.1
(ii) 8.64
(iii) 5-01
(iv) 0.0906
(v) 0.125
(vi) 111.11
(vii) 0.848 x 3
(viii)4.906 x (0.2) ²
(ix) (1.2)² x(0.9)²

(i)

2.1 ÷ 10 = 0.21,
2.1 ÷ 100 = 0.021,
2.1 ÷ 1000 = 0.0021

and
2.1 ÷10000 = 0.00021

(ii)

8.64 ÷ 10 = 0.864,

8.64 ÷ 100 = 0.0864,

8.64 ÷ 1000 = 0.00864

and

8.64 ÷ 10000 = 0.000864

(iii)

5.01 ÷ 10 = 0.501,

5.01 ÷ 100 = 0.0501,

5.01 ÷1000 = 0.00501,

5.01 ÷ 10000 = 0.000501

(iv)

0.0906 ÷ 10 = 0.00906,

0.0906 ÷ 100 = 0.000906,

0.0906 ÷ 1000 = 0.0090906,

0.0906 ÷ 10000 = 0.00000906

(v)

0.125 Now 0.125 + 10 = 0.0125,

0.125 ÷ 100 = 0-00125,

0.125 ÷1000 = 0.000125,

0.125 ÷ 10000 = 0.0000125

(vi)

111.11÷ 10= 11.111,

111.11÷ 100 = 1.1111,

111.11 ÷ 1000 = 0.11111,

111.11 ÷ 10000 = 0.011111

(vii)

0.848 x 3 = 2.544 ,

Now 2.544 ÷ 10 = 0.2544,

2.544 ÷ 100 = 0-02544,

2-544 ÷ 1000 = 0-002544,

2-544 ÷ 10000 = 0-0002544

(viii)

0.848 x 3 = 2.544 ,

Now 2.544 ÷ 10 = 0.2544,

2.544 ÷ 100 = 0-02544,

2-544 ÷ 1000 = 0-002544,

2-544 ÷ 10000 = 0-0002544

(ix)

(1.2)² x (0.9)²

= 1.2 x 1.2 x 0.9 x 0.9

= 1.44 x 0.81

= 1.1664

Now

1 .1664 + 10 = 0.11664,

1.1664 ÷ 100 = 0.011664,

1.1664 ÷ 1000 = 0.0011664,

1.1664 ÷ 10000 = 0.00011664

Question-6:-

Evaluate :
(i) 9.75 + 5
(ii) 4.4064 + 4
(iii) 27.69 + 30
(iv) 19.25 + 25
(v) 20.64+ 16
(vi) 3.204 + 9

(vii) 0.125 + 25
(viii) 0.14616 + 72
(ix) 0.6227+ 1300
(x) 257.894+ 0-169
(xi) 6.3 + (0.3)²

(i)

9.75 ÷ 5

= 1.95

(ii)

4.4064 ÷ 4

= 1.1016

(iii)

27.69 ÷ 30

= 0.923

(iv)

19.25 ÷ 25

= 0.77

(v)

20.64 ÷ 16

= 1.29

(vi)

3.204 ÷ 9

= 0.356

(vii)

0.125 ÷ 25

= 0.005

(Viii)

0.14616 ÷ 72

= 0.00203

(ix)

0.6227 ÷ 1300

= 0.000479

(x)

= 257894 ÷ 169

= 1526

(xi)

= 6.3 ÷ (0.3 × 0.3)

= 6.3 ÷ (0.09)

= 630 ÷ 09

= 630 ÷ 9

= 70

#### Question-7:-

Evaluate:
(i) 4.3 x 0.52 x 0.3
(ii) 3.2 x 2.5 x 0.7
(iii) 0.8 x 1.5 x 0.6
(iv) 0.3 x 0.3 x 0.3
(v) 1.2 x 1.2 x 0.4
(vi) 0.4 x 0.04 x 0.004
(vii) 0.5 x 0.6 x 0.7
(Viii) 0.5 x 0.06 x 0.007

(i)

4.3 x 0.52 x 0.3

= 0.6708

(ii)

3.2 x 2.5 x 0.7

= 5.600 or 5.6

(iii)

0.8 x 1.5 x 0.6

= 0.720 or 0.72

(iv)

0.3 x 0.3 x 0.3

= 0.027

(v)

1.2 x 1.2 x 0.4

= 0.576

(vi)

0.4 x 0.04 x 0.004

= 0.000064

(vii)

0.5 x 0.6 x 0.7

= 0.210 or 0.21

(viii)

0.5 x 0.06 x 0.007

= 0.00021

#### Question-8:-

Evaluate:
(i) (0.9)²
(ii) (0.6)² x 0.5
(iii) 0.3 x (0.5)²
(iv) (0.4)³
(v) (0.2)3 x 5
(vi) (0.2)3 x 0.05

(i)

(0.9)²

⇒ 0.9 x 0.9 = 0.81

(ii)

(0.6)² x 0.5

⇒ 0.6 x 0.6 x 0.5

⇒ 0.36 x 0.5 = 0.180 or 0.18

(iii)

0.3 x (0.5)2

⇒ 0.3 x 0.5 x 0.5

⇒ 0.3 x 0.25 = 0.075

(iv)

(0.4)3

⇒ 0.4 x 0.4 x 0.4

⇒ 0.16 x 0.4 = 0.064

(v)

(0.2)3 x 5

⇒ 0.2 x 0.2 x 0.2 x 5

⇒ 0.08 x 5 = 0.40 or 0.4

(vi)

(0.2)3 x 0.05

⇒ 0.2 x 0.2 x 0.2 x 0.05

⇒ 0.008 x 0.05 = 0.00040

#### Question-9:-

Find the cost of 36.75 kg wheat at the rate of ₹12.80 per kg.

Total weight of wheat = 36.75 kg

Cost of 1 kg of wheat = Rs. 12.80

∴ Cost of 36.75 kg of wheat

= 36.75 × 12.80

= Rs. 470.40

#### Question-10:-

The cost of a pen is ₹56.15. Find the cost of 16 such pens.

Total weight of wheat = 36.75 kg

Cost of 1 kg of wheat = Rs. 12.80

∴ Cost of 36.75 kg of wheat

= 36.75 × 12.80

= Rs. 470.40

#### Question-11:-

Evaluate:
(i) 0.0072 ÷ 0.06
(ii) 0.621 ÷ 0.3
(iii) 0.0532 ÷ 0.005
(iv) 0.01162 ÷ 0.14

(v) (7.5 x 40.4) ÷ 25
(vi) 2.1 ÷ (0.1 x 0.1)

(i) 0.0072 ÷ 0.06

(ii) 0.621 ÷ 0.3

(iii) 0.0532 ÷ 0.005

(iv) 0.01162 ÷ 0.14

(v) (7.5 x 40.4) ÷ 25

=  303/25

=12.12

(vi) 2.1 ÷ (0.1 x 0.1)

=210/1

=210

#### Question-12:-

Fifteen identical articles weigh 31.50 kg. Find the weight of each article.

Weight of 15 articles = 31.50 kg

∴ Weight of one article

= 31.50- 15

= 2.1 kg

#### Question-13:-

The product of two numbers is 211.2. If one of these two numbers is 16.5, find the other number.

The product of two numbers = 211.2

One number = 16.5

∴ Second number = 211.2 ÷ 16.5

#### Question-14:-

One dozen identical articles cost ₹45.96. Find the cost of each article.

Weight of one dozen articles = ₹45.96

One dozen = 12

∴ Cost of one article = 45.96 + 12

= ₹3.83

Exe-4 D

### Selina Concise Maths Solutions for ICSE Class-7

#### Question-1:-

Find whether the given division forms a terminating decimal or a non-terminating decimal:
(i) 3 ÷ 8
(ii)8 ÷ 3
(iii) 6÷ 5
(iv) 5 ÷ 6
(v) 12.5 ÷ 4
(vi) 23 ÷ 0.7
(vii) 42 ÷ 9
(viii) 0.56÷ 0.11

(i) 3 ÷ 8

3 ÷ 8 = 0.375

Therefore it is terminating decimal.

(ii) 8 ÷ 3

8 ÷ 3 = 2.666…

Therefore it is non – terminating decimal.

(iii) 6÷ 5

6 ÷ 5 = 1.2

Therefore it is terminating decimal.

(iv) 5 ÷ 6

5 ÷ 6 = 0.8333……

Therefore it is non – terminating decimal.

(v) 12.5 ÷ 4

12.5 ÷ 4 = 3.125

Therefore it is terminating decimal.

(vi) 23 ÷ 0.7

23 ÷ 0.7 = 230 ÷ 7 = 32.8571428….

Therefore it is non – terminating decimal.

(vii) 42 ÷ 9

42 ÷ 9 = 4.666…

Therefore it is non – terminating decimal.

(viii) 0.56÷ 0.11

0.56 ÷ 0.11 = 56 ÷ 11 = 5.0909….

Therefore it is non – terminating decimal.

#### Question-2:-

Express as recurring decimals : (i)

(ii)

(iii)

5/6 = 0.8333….

=0.83¯

(iv)

2/13 = 0.153846153846

= 0.153846

(v)

1/9 = 0.1111…

.=0.1¯

(vi)

17/90 = 0.1888…

.=0.18¯

(vii)

5/18 = 0.2777…

= 0.27¯

(viii)

7/12 = 0.58333….

=0.583¯

#### Question-3:-

Convert into vulgar fraction :
(i) 0. $\bar { 3 }$
(ii) 0. $\bar { 8 }$
(iii) 4. $\bar { 4 }$
(iv) 23. $\bar { 7 }$

(i)

(ii)

(iii)

(iv)

#### Question-4:-

Convert into vulgar fraction :
(i) 0. $\bar { 35 }$
(ii) 2. $\bar { 23 }$
(iii) 1. $\bar { 28 }$
(iv) 5. $\bar { 234 }$

(i)

(ii)

(iii)

(iv)

#### Question-5:-

Convert into vulgar fraction :
(i) 0 0.3 $\bar { 7 }$
(ii) 0.2 $\bar { 45 }$
(iii) 0.68 $\bar { 5 }$
(iv) 0.4 $\bar { 42 }$

(i)

(ii)

(iii)

(iv)

### Exercise-  4 E

Decimal Fractions ICSE Class-7th Mathematics

#### Question-1:-

Round off:
(i) 0 .07, 0.112, 3.59, 9.489 to the nearest tenths.
(ii) 0.627, 100.479, 0 065 and 0.024 to the nearest hundredths.
(iii) 4.83,0.86,451 .943 and 9.08 to the nearest whole number.

(i)

0.07 = 0.1,
0.112 = 0.1
3.59 = 3.6,
9.489 = 9.5

(ii)

0.627 = 0.63,
100.479 = 100.48
0.065 = 0.07,
0.024 = 0.02

(iii)

4.83 = 5,
0.86= 1,
451.943 = 452
9.08 = 9

#### Question-2:-

(i) 18 .35 x 1.2
(ii) 62.89 x 0.02

(i)

18 .35 x 1.2 = 22.02

(ii)

62.89 x 0.02 = 1.2578 = 1.26

#### Question-3:-

Write the number of significant figures (digits) in:
(i) 35.06
(ii) 0.35
(iii) 7.0068
(iv) 19 .0
(v) 0.0062
(vi) 0 4.2 x 0.6
(vii) 0.08 x 25
(viii) 3.6 ÷ 0.12 .

(i) 35.06

significant figures i.e. digits are 4

(ii) 0.35

significant figures are 2.

(iii) 7.0068

significant figures are 5

(iv) 19 .0

significant figures are 3

(v) 0.0062

significant figures are 2.

(vi) 0 4.2 x 0.6

2.52, significant figure are 3

(vii) 0.08 x 25

2.00 = 2 significant figure is 1.

(viii) 3.6 ÷ 0.12 .

360 ÷ 12 = 30

significant figure are 2.

#### Question-4:-

Write :
(i) 35.869,0 008426,4.952 and 382.7, correct lo three significant figures.
(ii) 60.974. 2.8753, 0.001789 and 400.04, correct to four significant figures.
(iii) 14.29462, 19.2, 46356.82 and 69, correct to five significant figures.

(i)

Correct to three significant figures are

35.869 → 35.9

0.008426 →0.00843

4.952→ 4.95

382.7 →383

(ii)

Correct to four significant figures

60.974 →60.97

2.8753 → 2.875

0.001789 → 0.001789

400.04 → 400.0

### (iii)

Correct to five significant figures

14.29462→ 14.295

19.2 → 19.200

46356.82 →46357

69 → 69.000

### Exercise 4 F

Decimal Fractions ICSE Class-7th Mathematics

### Question-1:-

The weight of an object is 3 .06 kg. Find the total weight of 48 similar objects.

Weight of one object = 3.06 kg

∴ Weight of 48 object = 3.06 × 48 = 146.88 kg

3.06
× 48
2448,
12240

16688

#### Question-2:-

Find die cost of 17.5 m cloth at the rate of Rs. 112.50 per metre.

Cost of 1 meter cloth = Rs. 112.50

∴ Cost of 17.5 m cloth

= Rs. 112.50 × 17.5

= Rs. 1968.750

= 1968.75

112.50
× 17.5

56250
787500
1125000

16688

#### Question-3:-

One kilogram of oil costs Rs. 73.40. Find the cost of 9.75 kilogram  of the oil.

Cost of 1 kg oil = Rs. 73.40

∴ Cost of 9.75 kg oil = Rs. 73.40 × 9.75

= Rs. 715.6500

= Rs. 715.65

73.40
×    9.75
36700
513800
6606000
7156500

#### Question-4:-

Total weight of 8 identical objects is 51.2 kg. Find the weight of each object.

Weight of 8 objects = 51.2 kg

∴ Weight of 1 object = 51.2 ÷ 8 kg = 6.4 kg

#### Question-5:-

18.5 m of cloth costs Rs. 666. Find the cost of 3.8 m cloth.

Cost of 18.5 m cloth = Rs. 666

Cost of 1 m cloth = Rs. 666 ÷18.5 and cost of 3.8 m cloth

= Rs. (666 ÷18.5) x 3.8 = Rs. (6660 ÷ 185) x 3.8

= Rs. 36 x 3.8 = Rs. 136.80

36

185)  6660
555
1110
1110
xxx

Question-6:-

Find die value of:
(i) 0.5 of Rs. 7.60 + 1.62 of Rs. 30
(ii) 2.3 of 7.3 kg + 0.9 of 0.48 kg
(iii) 6.25 of 8.4 – 4.7 of 3.24
(iv) 0.98 of 235 – 0 .09 of 3.2

(i) 0.5 of Rs. 7.60 + 1.62 of Rs. 30

= Rs. 3.80 + Rs. 48.60

= Rs. 52.40

(ii) 2.3 of 7.3 kg + 0.9 of 0.48 kg

= 16.79 kg + 0.432 kg

= 17.222 kg

(iii) 6.25 of 8.4 – 4.7 of 3.24

= 52.500 – 15.228

= 37.272

(iv) 0.98 of 235 – 0 .09 of 3.2

= 230.30 – 0.288

= 230.012

= 230.300

#### Question 7.

Evaluate:
(i) 5.6 – 1 .5 of 3.4
(ii) 4.8 ÷ 0.04 of 5
(iii) 0.72 of 80 + 0.2
(iv) 0.72 ÷ 80 of 0.2
(v) 6.45 + (3.9 – 1.75)
(vi) 0.12 of(0.104 – 0.02)+ 0.36 x 0.5

(i) 5.6 – 1 .5 of 3.4

3.4
× 1.5

170
340
5.10

= 5.6 – 5.1 = 0.5

(ii) 4.8 ÷ 0.04 of 5

= 4.8 ÷ 0.20

= 4.8 ÷ 0.2

= 48 ÷ 2

= 24

(iii) 0.72 of 80 + 0.2

= 57.60 ÷ 0.2

= 57.6 ÷ 0.2

=576 ÷ 2

= 288

(v) 6.45 + (3.9 – 1.75)

= 6.45 ÷ (3.90 – 1.75)

= 6.45 ÷ 2.15

= 645 ÷ 215

= 3

(vi) 0.12 of(0.104 – 0.02)+ 0.36 x 0.5

= 0.12 of 0.084 + 0.36 × 0.5

= 0.01008 + 0.180

= 0.19008

— End of Decimal Fractions Solutions :–

Thanks