Selina solutions concise mathematica class 7 icse Solutions for Chapter 4 decimal fractions decimals

Q1) 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

Q2) Convert into decimal fractions

(i) 2\frac{4}{5}

(ii) \frac{79}{100}

(iii) \frac{37}{10000}

(iv) \frac{7543}{10000}

(v) \frac{3}{4}

(vi) 9\frac{3}{5}

(vii) 8\frac{5}{8}

(viii) 5\frac{7}{8}

Q3) 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

Q4) 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

Q5) 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

Q1) Add:

(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

Q2) 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

Q2) Subtract the first number from the second:

(i) 5.4, 9.8

(ii) 0.16, 4.3

(iii) 0.82, 8.6

(iv) 0.07, 8.43

(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

Q3) 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 – 25.90 – 100

(viii) 38.00 – 30 + 200.200 – 0.230

(ix) 555.555 + 55.555 – 5.55 – 0.5

Q4) Find the difference between 6.85 and 0.685.

Q5) Take out the sum of 19.38 and 56.025 then subtract it from 200.111.

Q6) Add 13.95 and 1.003; and from the result, subtract the sum of 2.794 and 6.2.

Q7) What should be added to 39.587 to give 80.375?

Q8) What should be subtracted from 100 to give 19.29?

Q9) What is the excess of 584.29 over 213.95?

Q10) 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)

Q11) What is the excess of 75 over 48.29?

Q12) If A=237.98 and B = 83.47

Find:

(i) A – B

(ii) B – A

Q13) The cost of one kg of sugar increases from 28.47 to 32.65. Find the increase in cost.

Q1) 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) 4.6 by 2.1

(vii) 0.568 by 6.4

Q3) Evaluate:

(i) 5.897\times2.3

(ii) 0.894\times87

(iii) 0.01\times0.001

(iv) 0.84\times2.2\times4

(v) 4.75\times0.08\times3

(vi) 2.4\times3.5\times4.8

(vii) 0.08\times1.2\times0.25

(viii) 0.3\ \times0.03\times0.003

(ix) 12.003\times\left(0.2\right)^5

Q4) 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

Q5) 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\times3

(viii) 4.906\times\left(0.2\right)^2

(ix) \left(1.2\right)^2\times\left(0.9\right)^2

Q6) Evaluate:

(i) 9.75\div5

(ii) 4.4064\div4

(iii) 27.69\div30

(iv) 19.25\div25

(v) 20.64\div16

(vi) 3.204\div9

(vii) 0.125\div25

(viii) 0.14616\div72

(ix) 0.6227\div1300

(x) 257.894\div0.169

(xi) 6.3\div\left(0.3\right)^2

Q7) Evaluate:

(i) 4.3\times0.52\times0.3

(ii) 3.2\times2.5\times0.7

(iii) 0.8\times1.5\times0.6

(iv) 0.3\times0.3\times0.3

(v) 1.2\times1.2\times0.4

(vi) 0.4\times0.04\times0.004

(vii) 0.5\times0.6\times0.7

(viii) 0.5\times0.06\times0.007

Q8) Evaluate:

(i) \left(0.9\right)^2

(ii) \left(0.6\right)^2\times0.5

(iii) 0.3\ \times\ \left(0.5\right)^2

(iv) \left(0.4\right)^3

(v) \left(0.2\right)^3\times5

(vi) \left(0.2\right)^3\times0.05

Q9) Find the cost of 36.75kg of wheat at the rate of rs. 12.80 per kg.

Q10) The cost of a pen is Rs. 56.15. Find the cost of 16 such pens.

Q11) Evaluate:

(i) 0.0072\div0.06

(ii) 0.621\div0.3

(iii) 0.0532\div0.005

(iv) 0.01162\div0.14

(v) \left(7.5\times40.4\right)\div25

(vi) 2.1\div\left(0.1\times0.1\right)

Q12) Fifteen identical articles weigh 31.50 kg. Find the weight of each articles.

Q13) The product of two numbers is 211.2. If one of these two numbers is 16.5, find the other number.

Q14) One dozen identical articles cost Rs. 45.96. Find the cost of each article.

Q1) Find whether the given division forms a terminating decimal or a non-terminating decimal:

(i) 3\div8

(ii) 8\div3

(iii) 6\div5

(iv) 5\div6

(v) 12.5\div4

(vi) 23\div0.7

(vii) 42\div9

(viii) 0.56\div0.11

Q2) Express as recurring decimals

(i) 1\frac{1}{3}

(ii) \frac{10}{11}

(iii) \frac{5}{6}

(iv) \frac{2}{13}

(v) \frac{1}{9}

(vi) \frac{17}{90}

(vii) \frac{5}{18}

(viii) \frac{7}{12}

Q3) Convert into vulgar fraction:

(i) 0.\overline{3}

(ii) 0.\overline{8}

(iii) 4.\overline{4}

(iv) 23.\overline{7}

Q4) Convert into vulgar fraction:

(i) 0.\overline{35}

(ii) 2.\overline{23}

(iii) 1.\overline{28}

(iv) 5.\overline{234}

Q5) Convert into vulgar fraction:

(i) 0.3\overline{7}

(ii) 0.2\overline{45}

(iii) 0.68\overline{5}

(iv) 0.4\overline{42}

Q1) 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.

Q2) Simplify and write your answers correct to the nearest hundredths:

(i) 18.35\times1.2

(ii) 62.89\times0.02

Q3) Write the number of significant figures (digits) in:

(i) 35.06

(ii) 0.35

(iii) 7.0068

(iv) 19.0

(v) 0.0062

(vi) 4.2\times0.6

(vii) 0.08\times25

(viii) 3.6\div0.12

Q4) Write:

(i) 35.869, 0.008426, 4.952, 382.7 correct to 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.

Q1) The weight of an object is 3.06kg. Find the total weight of 48 similar objects.

Q2) Find die cost of 17.5m cloth at the rate of Rs. 112.50 per metre.

Q3) One kilogramme of oil costs Rs. 73.40. Find the cost of 9.75 kilogrammes of oil.

Q4) Total weight of 8 identical objects is 51.2 kg. Find the weight of each object.

Q5) 18.5m of cloth costs Rs. 666. Find the cost of 3.8m cloth.

Q6) Find die value of:

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

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

(iii) 6.25 of 8.4 – 4.7 of 3.24

(iv) 0.98 of 235 – 0.09 of 3.2

Q7) Evaluate:

(i) 5.6\ -\ 1.5\ of\ 3.4

(ii) 4.8\div0.04\ of\ 5

(iii) 0.72\ of\ 80\ \div0.2

(iv) 0.72\div80\ of\ 0.2

(v) 6.45\ \div\left(3.9-1.75\right)

(vi) 0.12\ of\ \left(0.104\ -\ 0.02\right)\div0.36\ \times0.5