Page 1 Exercise 7.2 page: 7.9 1. Write each of the following as decimals: (i) Three tenths (ii) Two ones and five tenths (iii) Thirty and one tenths (iv) Twenty two and six tenths (v) One hundred, two ones and three tenths Solution: (i) Three tenths It can be written as 3/10 = 0.3 (ii) Two ones and five tenths It can be written as 2 + 5/10 = 2.5 (iii) Thirty and one tenths It can be written as 30 + 1/10 = 30.1 (iv) Twenty two and six tenths It can be written as 22 + 6/10 = 22.6 (v) One hundred, two ones and three tenths It can be written as 100 + 2 + 3/10 = 102.3 2. Write each of the following as decimals: (i) 30 + 6 + 2/10 (ii) 700 + 5 + 7/10 (iii) 200 + 60 + 5 + 1/10 (iv) 200 + 70 + 9 + 5/10 Solution: (i) 30 + 6 + 2/10 In the above question We know that 3 tens, 6 ones and 2 tenths Hence, the decimal is 36.2. (ii) 700 + 5 + 7/10 In the above question We know that 7 hundreds, 5 ones and 7 tenths Hence, the decimal is 705.7. (iii) 200 + 60 + 5 + 1/10 Page 2 Exercise 7.2 page: 7.9 1. Write each of the following as decimals: (i) Three tenths (ii) Two ones and five tenths (iii) Thirty and one tenths (iv) Twenty two and six tenths (v) One hundred, two ones and three tenths Solution: (i) Three tenths It can be written as 3/10 = 0.3 (ii) Two ones and five tenths It can be written as 2 + 5/10 = 2.5 (iii) Thirty and one tenths It can be written as 30 + 1/10 = 30.1 (iv) Twenty two and six tenths It can be written as 22 + 6/10 = 22.6 (v) One hundred, two ones and three tenths It can be written as 100 + 2 + 3/10 = 102.3 2. Write each of the following as decimals: (i) 30 + 6 + 2/10 (ii) 700 + 5 + 7/10 (iii) 200 + 60 + 5 + 1/10 (iv) 200 + 70 + 9 + 5/10 Solution: (i) 30 + 6 + 2/10 In the above question We know that 3 tens, 6 ones and 2 tenths Hence, the decimal is 36.2. (ii) 700 + 5 + 7/10 In the above question We know that 7 hundreds, 5 ones and 7 tenths Hence, the decimal is 705.7. (iii) 200 + 60 + 5 + 1/10 In the above question We know that 2 hundreds, 6 tens, 5 ones and 1 tenths. Hence, the decimal is 265.1. (iv) 200 + 70 + 9 + 5/10 In the above question We know that 2 hundreds, 7 tens, 9 ones and 5 tenths Hence, the decimal is 279.5. 3. Write each of the following as decimals: (i) 22/10 (ii) 3/2 (iii) 2/5 Solution: (i) 22/10 Here the denominator is ten Hence, the decimal is 2.2 (ii) 3/2 Multiplying the fraction by 5 We get (3/2) × (5/5) = 15/10 = 1.5 (iii) 2/5 Multiplying the fraction by 2 We get (2/5) × (2/2) = 4/10 = 0.4 4. Write each of the following as decimals: (i) 40 2/5 (ii) 39 2/10 (iii) 4 3/5 (iv) 25 1/2 Solution: (i) 40 2/5 In order to write in decimal we should make the denominator 10 So we get 40 + [(2/5) × (2/2)] = 40 + 4/10 = 40.4 (ii) 39 2/10 It can be written as 39 + 2/10 = 39 + 0.2 = 39.2 (iii) 4 3/5 In order to write in decimal we should make the denominator 10 So we get Page 3 Exercise 7.2 page: 7.9 1. Write each of the following as decimals: (i) Three tenths (ii) Two ones and five tenths (iii) Thirty and one tenths (iv) Twenty two and six tenths (v) One hundred, two ones and three tenths Solution: (i) Three tenths It can be written as 3/10 = 0.3 (ii) Two ones and five tenths It can be written as 2 + 5/10 = 2.5 (iii) Thirty and one tenths It can be written as 30 + 1/10 = 30.1 (iv) Twenty two and six tenths It can be written as 22 + 6/10 = 22.6 (v) One hundred, two ones and three tenths It can be written as 100 + 2 + 3/10 = 102.3 2. Write each of the following as decimals: (i) 30 + 6 + 2/10 (ii) 700 + 5 + 7/10 (iii) 200 + 60 + 5 + 1/10 (iv) 200 + 70 + 9 + 5/10 Solution: (i) 30 + 6 + 2/10 In the above question We know that 3 tens, 6 ones and 2 tenths Hence, the decimal is 36.2. (ii) 700 + 5 + 7/10 In the above question We know that 7 hundreds, 5 ones and 7 tenths Hence, the decimal is 705.7. (iii) 200 + 60 + 5 + 1/10 In the above question We know that 2 hundreds, 6 tens, 5 ones and 1 tenths. Hence, the decimal is 265.1. (iv) 200 + 70 + 9 + 5/10 In the above question We know that 2 hundreds, 7 tens, 9 ones and 5 tenths Hence, the decimal is 279.5. 3. Write each of the following as decimals: (i) 22/10 (ii) 3/2 (iii) 2/5 Solution: (i) 22/10 Here the denominator is ten Hence, the decimal is 2.2 (ii) 3/2 Multiplying the fraction by 5 We get (3/2) × (5/5) = 15/10 = 1.5 (iii) 2/5 Multiplying the fraction by 2 We get (2/5) × (2/2) = 4/10 = 0.4 4. Write each of the following as decimals: (i) 40 2/5 (ii) 39 2/10 (iii) 4 3/5 (iv) 25 1/2 Solution: (i) 40 2/5 In order to write in decimal we should make the denominator 10 So we get 40 + [(2/5) × (2/2)] = 40 + 4/10 = 40.4 (ii) 39 2/10 It can be written as 39 + 2/10 = 39 + 0.2 = 39.2 (iii) 4 3/5 In order to write in decimal we should make the denominator 10 So we get 4 + [(3/5) × (2/2)] = 4 + 6/10 = 4.6 (iv) 25 1/2 In order to write in decimal we should make the denominator 10 So we get 25+ [(1/2) × (5/5)] = 25 + 5/10 = 25.5 5. Write the following decimals as fractions. Reduce the fractions to lowest form: (i) 3.8 (ii) 21.2 (iii) 6.4 (iv) 1.0 Solution: (i) 3.8 It can be written as = 3 + 8 tenths On further calculation = 3 + 8/10 We get = 3(10/10) + 8/10 By further simplification = 30/10 + 8/10 = 38/10 So we get = 19/5 (ii) 21.2 It can be written as = 21 + 2 tenths On further calculation = 21 + 2/10 We get = 21(10/10) + 2/10 By further simplification = 210/10 + 2/10 = 212/10 So we get = 106/5 (iii) 6.4 It can be written as = 6 + 4 tenths On further calculation = 6 + 4/10 We get = 6(10/10) + 4/10 By further simplification = 60/10 + 4/10 = 64/10 Page 4 Exercise 7.2 page: 7.9 1. Write each of the following as decimals: (i) Three tenths (ii) Two ones and five tenths (iii) Thirty and one tenths (iv) Twenty two and six tenths (v) One hundred, two ones and three tenths Solution: (i) Three tenths It can be written as 3/10 = 0.3 (ii) Two ones and five tenths It can be written as 2 + 5/10 = 2.5 (iii) Thirty and one tenths It can be written as 30 + 1/10 = 30.1 (iv) Twenty two and six tenths It can be written as 22 + 6/10 = 22.6 (v) One hundred, two ones and three tenths It can be written as 100 + 2 + 3/10 = 102.3 2. Write each of the following as decimals: (i) 30 + 6 + 2/10 (ii) 700 + 5 + 7/10 (iii) 200 + 60 + 5 + 1/10 (iv) 200 + 70 + 9 + 5/10 Solution: (i) 30 + 6 + 2/10 In the above question We know that 3 tens, 6 ones and 2 tenths Hence, the decimal is 36.2. (ii) 700 + 5 + 7/10 In the above question We know that 7 hundreds, 5 ones and 7 tenths Hence, the decimal is 705.7. (iii) 200 + 60 + 5 + 1/10 In the above question We know that 2 hundreds, 6 tens, 5 ones and 1 tenths. Hence, the decimal is 265.1. (iv) 200 + 70 + 9 + 5/10 In the above question We know that 2 hundreds, 7 tens, 9 ones and 5 tenths Hence, the decimal is 279.5. 3. Write each of the following as decimals: (i) 22/10 (ii) 3/2 (iii) 2/5 Solution: (i) 22/10 Here the denominator is ten Hence, the decimal is 2.2 (ii) 3/2 Multiplying the fraction by 5 We get (3/2) × (5/5) = 15/10 = 1.5 (iii) 2/5 Multiplying the fraction by 2 We get (2/5) × (2/2) = 4/10 = 0.4 4. Write each of the following as decimals: (i) 40 2/5 (ii) 39 2/10 (iii) 4 3/5 (iv) 25 1/2 Solution: (i) 40 2/5 In order to write in decimal we should make the denominator 10 So we get 40 + [(2/5) × (2/2)] = 40 + 4/10 = 40.4 (ii) 39 2/10 It can be written as 39 + 2/10 = 39 + 0.2 = 39.2 (iii) 4 3/5 In order to write in decimal we should make the denominator 10 So we get 4 + [(3/5) × (2/2)] = 4 + 6/10 = 4.6 (iv) 25 1/2 In order to write in decimal we should make the denominator 10 So we get 25+ [(1/2) × (5/5)] = 25 + 5/10 = 25.5 5. Write the following decimals as fractions. Reduce the fractions to lowest form: (i) 3.8 (ii) 21.2 (iii) 6.4 (iv) 1.0 Solution: (i) 3.8 It can be written as = 3 + 8 tenths On further calculation = 3 + 8/10 We get = 3(10/10) + 8/10 By further simplification = 30/10 + 8/10 = 38/10 So we get = 19/5 (ii) 21.2 It can be written as = 21 + 2 tenths On further calculation = 21 + 2/10 We get = 21(10/10) + 2/10 By further simplification = 210/10 + 2/10 = 212/10 So we get = 106/5 (iii) 6.4 It can be written as = 6 + 4 tenths On further calculation = 6 + 4/10 We get = 6(10/10) + 4/10 By further simplification = 60/10 + 4/10 = 64/10 So we get = 32/5 (iv) 1.0 Here, the number after decimal is zero so the fraction is 1. 6. Represent the following decimal numbers on the number line: (i) 0.2 (ii) 1.9 (iii) 1.1 (iv) 2.5 Solution: (i) 0.2 can be represented on the number line as given below: (ii) 1.9 can be represented on the number line as given below: (iii) 1.1 can be represented on the number line as given below: (iv) 2.5 can be represented on the number line as given below: 7. Between which two whole numbers on the number line are the given numbers? Which one is nearer the number? (i) 0.8 (ii) 5.1 (iii) 2.6 (iv) 6.4 (v) 9.0 (vi) 4.9 Solution: (i) We know that 0.8 is 8 units from 0 and 2 units from 1 Hence, it is nearer to 1. Page 5 Exercise 7.2 page: 7.9 1. Write each of the following as decimals: (i) Three tenths (ii) Two ones and five tenths (iii) Thirty and one tenths (iv) Twenty two and six tenths (v) One hundred, two ones and three tenths Solution: (i) Three tenths It can be written as 3/10 = 0.3 (ii) Two ones and five tenths It can be written as 2 + 5/10 = 2.5 (iii) Thirty and one tenths It can be written as 30 + 1/10 = 30.1 (iv) Twenty two and six tenths It can be written as 22 + 6/10 = 22.6 (v) One hundred, two ones and three tenths It can be written as 100 + 2 + 3/10 = 102.3 2. Write each of the following as decimals: (i) 30 + 6 + 2/10 (ii) 700 + 5 + 7/10 (iii) 200 + 60 + 5 + 1/10 (iv) 200 + 70 + 9 + 5/10 Solution: (i) 30 + 6 + 2/10 In the above question We know that 3 tens, 6 ones and 2 tenths Hence, the decimal is 36.2. (ii) 700 + 5 + 7/10 In the above question We know that 7 hundreds, 5 ones and 7 tenths Hence, the decimal is 705.7. (iii) 200 + 60 + 5 + 1/10 In the above question We know that 2 hundreds, 6 tens, 5 ones and 1 tenths. Hence, the decimal is 265.1. (iv) 200 + 70 + 9 + 5/10 In the above question We know that 2 hundreds, 7 tens, 9 ones and 5 tenths Hence, the decimal is 279.5. 3. Write each of the following as decimals: (i) 22/10 (ii) 3/2 (iii) 2/5 Solution: (i) 22/10 Here the denominator is ten Hence, the decimal is 2.2 (ii) 3/2 Multiplying the fraction by 5 We get (3/2) × (5/5) = 15/10 = 1.5 (iii) 2/5 Multiplying the fraction by 2 We get (2/5) × (2/2) = 4/10 = 0.4 4. Write each of the following as decimals: (i) 40 2/5 (ii) 39 2/10 (iii) 4 3/5 (iv) 25 1/2 Solution: (i) 40 2/5 In order to write in decimal we should make the denominator 10 So we get 40 + [(2/5) × (2/2)] = 40 + 4/10 = 40.4 (ii) 39 2/10 It can be written as 39 + 2/10 = 39 + 0.2 = 39.2 (iii) 4 3/5 In order to write in decimal we should make the denominator 10 So we get 4 + [(3/5) × (2/2)] = 4 + 6/10 = 4.6 (iv) 25 1/2 In order to write in decimal we should make the denominator 10 So we get 25+ [(1/2) × (5/5)] = 25 + 5/10 = 25.5 5. Write the following decimals as fractions. Reduce the fractions to lowest form: (i) 3.8 (ii) 21.2 (iii) 6.4 (iv) 1.0 Solution: (i) 3.8 It can be written as = 3 + 8 tenths On further calculation = 3 + 8/10 We get = 3(10/10) + 8/10 By further simplification = 30/10 + 8/10 = 38/10 So we get = 19/5 (ii) 21.2 It can be written as = 21 + 2 tenths On further calculation = 21 + 2/10 We get = 21(10/10) + 2/10 By further simplification = 210/10 + 2/10 = 212/10 So we get = 106/5 (iii) 6.4 It can be written as = 6 + 4 tenths On further calculation = 6 + 4/10 We get = 6(10/10) + 4/10 By further simplification = 60/10 + 4/10 = 64/10 So we get = 32/5 (iv) 1.0 Here, the number after decimal is zero so the fraction is 1. 6. Represent the following decimal numbers on the number line: (i) 0.2 (ii) 1.9 (iii) 1.1 (iv) 2.5 Solution: (i) 0.2 can be represented on the number line as given below: (ii) 1.9 can be represented on the number line as given below: (iii) 1.1 can be represented on the number line as given below: (iv) 2.5 can be represented on the number line as given below: 7. Between which two whole numbers on the number line are the given numbers? Which one is nearer the number? (i) 0.8 (ii) 5.1 (iii) 2.6 (iv) 6.4 (v) 9.0 (vi) 4.9 Solution: (i) We know that 0.8 is 8 units from 0 and 2 units from 1 Hence, it is nearer to 1. (ii) We know that 5.1 is 1 unit from 5 and 9 units from 6 Hence, it is nearer to 5. (iii) We know that 2.6 is 6 units from 2 and 4 units from 3 Hence, it is nearer to 3. (iv) We know that 6.4 is 4 units from 6 and 6 units from 7 Hence, it is nearer to 6. (v) We know that 9.0 is a whole number Hence, it is nearer to 9. (vi) We know that 4.9 is 9 units from 4 and 1 unit from 5 Hence, it is nearer to 5. 8. Write the decimal number represented by the points on the given number line: A, B, C, D. Solution: A – We know that A is at eighth place between the numbers 0 and 1 Hence, the decimal is 0.8 B – We know that B is at third place between the numbers 1 and 2 Hence, the decimal is 1.3 C – We know that C is at ninth place between the numbers 1 and 2 Hence, the decimal is 1.9 D – We know that D is at sixth place between the numbers 2 and 3 Hence, the decimal is 2.6Read More

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