Decimals (Exercise 7.8) RD Sharma Solutions | Mathematics (Maths) Class 6 PDF Download

 Page 1


 
 
 
 
 
 
Exercise 7.8                                                                             page: 7.28 
1. Find the sum in each of the following: 
 
Solution: 
 
(i) We know that 
102.360 + 7.054 + 0.800 = 110.214 
 
(ii) We know that 
0.060 + 4.108 + 91.500 = 95.668 
 
(iii) We know that 
312.800 + 290.020 + 128.457 = 731.277 
 
(iv) We know that 
113.285 + 6.700 + 9.340 + 30.080 = 159.405 
 
(v) We know that 
3.42 + 264.08 + 7.6 + 95.321 = 370.421 
 
(vi) We know that 
18.003 + 41.700 + 10.950 + 5.057 = 75.710 
 
2. Add the following: 
(i) 41.8, 39.24, 5.01 and 62.6 
(ii) 4.702, 4.2, 6.02 and 1.27 
(iii) 18.03, 146.3, 0.829 and 5.324 
Solution: 
 
(i) 41.8, 39.24, 5.01 and 62.6 
It can be written as 
41.80 + 39.24 + 5.01 + 62.60 = 148.65 
 
(ii) 4.702, 4.2, 6.02 and 1.27 
It can be written as 
4.702 + 4.200 + 6.020 + 1.270 = 16.192 
 
(iii) 18.03, 146.3, 0.829 and 5.324 
It can be written as 
Page 2


 
 
 
 
 
 
Exercise 7.8                                                                             page: 7.28 
1. Find the sum in each of the following: 
 
Solution: 
 
(i) We know that 
102.360 + 7.054 + 0.800 = 110.214 
 
(ii) We know that 
0.060 + 4.108 + 91.500 = 95.668 
 
(iii) We know that 
312.800 + 290.020 + 128.457 = 731.277 
 
(iv) We know that 
113.285 + 6.700 + 9.340 + 30.080 = 159.405 
 
(v) We know that 
3.42 + 264.08 + 7.6 + 95.321 = 370.421 
 
(vi) We know that 
18.003 + 41.700 + 10.950 + 5.057 = 75.710 
 
2. Add the following: 
(i) 41.8, 39.24, 5.01 and 62.6 
(ii) 4.702, 4.2, 6.02 and 1.27 
(iii) 18.03, 146.3, 0.829 and 5.324 
Solution: 
 
(i) 41.8, 39.24, 5.01 and 62.6 
It can be written as 
41.80 + 39.24 + 5.01 + 62.60 = 148.65 
 
(ii) 4.702, 4.2, 6.02 and 1.27 
It can be written as 
4.702 + 4.200 + 6.020 + 1.270 = 16.192 
 
(iii) 18.03, 146.3, 0.829 and 5.324 
It can be written as 
 
 
 
 
 
 
18.030 + 146.300 + 0.829 + 5.324 = 170.483 
 
3. Find the sum in each of the following: 
(i) 0.007 + 8.5 + 30.08 
(ii) 280.69 + 25.2 + 38 
(iii) 25.65 + 9.005 + 3.7 
(iv) 27.076 + 0.55 + 0.004 
Solution: 
 
(i) 0.007 + 8.5 + 30.08 
It can be written as 
0.007 + 8.500 + 30.080 = 38.587 
 
(ii) 280.69 + 25.2 + 38 
It can be written as 
280.69 + 25.20 + 38.00 = 343.89 
 
(iii) 25.65 + 9.005 + 3.7 
It can be written as 
25.650 + 9.005 + 3.700 = 38.355 
 
(iv) 27.076 + 0.55 + 0.004 
It can be written as 
27.076 + 0.550 + 0.004 = 27.630 
 
4. Radhika’s mother gave her Rs 10.50 and her father gave her Rs 15.80, find the total amount given to 
Radhika by her parents. 
Solution: 
 
Amount given by Radhika’s mother = Rs 10.50 
Amount given by Radhika’s father = Rs 15.80 
So the total amount given by her parents = Rs 10.50 + Rs 15.80 = Rs 26.30 
 
Hence, the total amount given by her parents is Rs 26.30. 
 
5. Rahul bought 4 kg 90 g apples, 2 kg 60 g of grapes and 5 kg 300 g of mangoes. Find the weight of the 
fruits he bought in all. 
Solution: 
 
Weight of apples bought by Rahul = 4 kg 90 g = 4.090 kg 
Weight of grapes bought by Rahul = 2 kg 60 g = 2.060 kg 
Weight of mangoes bought by Rahul = 5 kg 300 g = 5.300 kg 
So the weight of all the fruits = 4.090 + 2.060 + 5.300 = 11.450 kg 
 
Hence, the weight of the fruits bought by Rahul is 11.450 kg. 
 
6. Nasreen bought 3 m 20 cm cloth for her shirt and 2 m 5 cm cloth for skirt. Find the total cloth bought by 
her. 
Solution: 
 
Page 3


 
 
 
 
 
 
Exercise 7.8                                                                             page: 7.28 
1. Find the sum in each of the following: 
 
Solution: 
 
(i) We know that 
102.360 + 7.054 + 0.800 = 110.214 
 
(ii) We know that 
0.060 + 4.108 + 91.500 = 95.668 
 
(iii) We know that 
312.800 + 290.020 + 128.457 = 731.277 
 
(iv) We know that 
113.285 + 6.700 + 9.340 + 30.080 = 159.405 
 
(v) We know that 
3.42 + 264.08 + 7.6 + 95.321 = 370.421 
 
(vi) We know that 
18.003 + 41.700 + 10.950 + 5.057 = 75.710 
 
2. Add the following: 
(i) 41.8, 39.24, 5.01 and 62.6 
(ii) 4.702, 4.2, 6.02 and 1.27 
(iii) 18.03, 146.3, 0.829 and 5.324 
Solution: 
 
(i) 41.8, 39.24, 5.01 and 62.6 
It can be written as 
41.80 + 39.24 + 5.01 + 62.60 = 148.65 
 
(ii) 4.702, 4.2, 6.02 and 1.27 
It can be written as 
4.702 + 4.200 + 6.020 + 1.270 = 16.192 
 
(iii) 18.03, 146.3, 0.829 and 5.324 
It can be written as 
 
 
 
 
 
 
18.030 + 146.300 + 0.829 + 5.324 = 170.483 
 
3. Find the sum in each of the following: 
(i) 0.007 + 8.5 + 30.08 
(ii) 280.69 + 25.2 + 38 
(iii) 25.65 + 9.005 + 3.7 
(iv) 27.076 + 0.55 + 0.004 
Solution: 
 
(i) 0.007 + 8.5 + 30.08 
It can be written as 
0.007 + 8.500 + 30.080 = 38.587 
 
(ii) 280.69 + 25.2 + 38 
It can be written as 
280.69 + 25.20 + 38.00 = 343.89 
 
(iii) 25.65 + 9.005 + 3.7 
It can be written as 
25.650 + 9.005 + 3.700 = 38.355 
 
(iv) 27.076 + 0.55 + 0.004 
It can be written as 
27.076 + 0.550 + 0.004 = 27.630 
 
4. Radhika’s mother gave her Rs 10.50 and her father gave her Rs 15.80, find the total amount given to 
Radhika by her parents. 
Solution: 
 
Amount given by Radhika’s mother = Rs 10.50 
Amount given by Radhika’s father = Rs 15.80 
So the total amount given by her parents = Rs 10.50 + Rs 15.80 = Rs 26.30 
 
Hence, the total amount given by her parents is Rs 26.30. 
 
5. Rahul bought 4 kg 90 g apples, 2 kg 60 g of grapes and 5 kg 300 g of mangoes. Find the weight of the 
fruits he bought in all. 
Solution: 
 
Weight of apples bought by Rahul = 4 kg 90 g = 4.090 kg 
Weight of grapes bought by Rahul = 2 kg 60 g = 2.060 kg 
Weight of mangoes bought by Rahul = 5 kg 300 g = 5.300 kg 
So the weight of all the fruits = 4.090 + 2.060 + 5.300 = 11.450 kg 
 
Hence, the weight of the fruits bought by Rahul is 11.450 kg. 
 
6. Nasreen bought 3 m 20 cm cloth for her shirt and 2 m 5 cm cloth for skirt. Find the total cloth bought by 
her. 
Solution: 
 
 
 
 
 
 
 
Cloth bought by Nasreen for shirt = 3 m 20 cm = 3.20 m 
Cloth bought by Nasreen for skirt = 2 m 50 cm = 2.05 m 
So the total cloth bought by her = 3.20 + 2.05 = 5.25 m = 5 m 25 cm 
 
Hence, the total cloth bought by her is 5 m 25 cm. 
 
7. Sunita travels 15 km 268 m by bus, 7 km 7 m by car and 500 m by foot in order to reach her school. How 
far is her school from her residence? 
Solution: 
 
Distance travelled by Sunita by bus = 15 km 268 m = 15.268 km 
Distance travelled by Sunita by car = 7 km 7 m = 7.007 km 
Distance travelled by Sunita by foot = 500 m = 0.500 km 
So the distance from residence to school = 15.268 + 7.007 + 0.500 = 22.775 km 
 
Hence, the distance from her residence to school is 22.775 km.