Exercise 7.1
Question 1: Write the following decimals in the place value table:
(i) 52.5
(ii) 12.57
(iii) 15.05
(iv) 74.059
(v) 0.503
Solution 1:
Question 2: Write the decimals shown in the following place value table:
Solution 2:
(i) Decimal Expiration 307.12
(ii) Decimal Expiration 9543.025
(iii) Decimal Expiration 12.503
Question 3: Write each of the following decimals in words:
(i) 175.04
(ii) 0.21
(iii) 9.004
(iv) 0.459
Solution 3:
Solution 8:
(A) Location of Point A on number line is 0.8.
(B) Location of Point B on number line is 1.3.
(C) Location of Point C on number line is 1.9.
(D) Location of Point C on number line is 2.96.
Exercise 7.4
Exercise 7.5
Question 1: Fill in the blanks by using > or < to complete the following:
Question 2: Which is greater? Give reason for your answer?
(i) 1.008 or 1.800
(ii) 3.3 or 3.300
(iii) 5.64 or 5.603
(iv) 1.5 or 1.50
(v) 1.431 or 1.439
(vi) 0.5 or 0.05
Solution 2:
Exercise 7.6
Exercise 7.7
Question 1: Choose the decimal (s) from the brackets which is (are) not equivalent to the given decimals:
(i) 0.8 (0.80, 0.85, 0.800, 0.08)
(ii) 25.1 (25.01, 25.10, 25.100, 25.001)
(iii) 45.05 (45.050, 45.005, 45.500, 45.0500)
Solution 1:
(i) 0.8 (0.80, 0.85, 0.800, 0.08)
0.8 = 0.80, 0.800
0.8 0.85, 0.08
(ii) 25.1 (25.01, 25.10, 25.100, 25.001)
25.1 = 25.10, 25.100
25.1 25.01, 25.001
(iii) 45.05 (45.050, 45.005, 45.500, 45.0500)
45.05 = 45.050, 45.0500
45.05 45.005, 45.500
Question 2: Which of the following are like decimals:
(i) 0.34, 0.07, 5.35, 24.70
(ii) 45.05, 4.505, 20.55, 20.5
(iii) 8.80, 17.08, 8.94, 0.27
(iv) 4.50, 16.80, 0.700, 7.08
Solution 2:
(i) 0.34, 0.07, 5.35, 24.70
In the given expression all the values are like decimals because the numbers of digits after decimal are equal.
(ii) 45.05, 4.505, 20.55, 20.5
In the given expression all the values are unlike decimals as the numbers of digits after decimal are not equal.
(iii) 8.80, 17.08, 8.94, 0.27
In the given expression all the values are like decimals because the numbers of digits after decimal are equal.
(iv) 4.50, 16.80, 0.700, 7.08
In the given expression all the values are unlike decimals as the numbers of digits after decimal are not equal.
Question 3: Which of the following statements are correct?
(i) 8.05 and 7.95 are like decimals.
(ii) 0.95, 0.306, 7.10 are unlike decimals.
(iii) 3.70 and 3.7 are like decimals.
(iv) 13.59, 1.359, 135.9 are like decimals.
(v) 5.60, 3.04, 0.45 are like decimals.
Solution 3:
Question 4: Convert each of the following sets of unlike decimals to like decimal:
(i) 7.8, 7.85
(ii) 2.02, 3.2
(iii) 0.6, 5.8, 12.765
(iv) 5.296, 5.2, 5.29
(v) 4.3294, 43.29, 432.94
Solution 4:
(i) 7.8, 7.85
In 7.8 there is 1 digit after decimal.
In 7.85 there are 2 digits after decimal.
7.85 contains 2 digits after decimal point so by changing 7.8 as 7.80
Hence, 7.80 and 7.85 are like decimals.
(ii) 2.02, 3.2
In 2.02 there are 2 digits after decimal.
In 3.2 there is 1 digit after decimal.
2.02 contains 2 digits after decimal point so by changing 3.2 as 3.20
Hence, 2.02 and 3.20 are like decimals.
(iii) 0.6, 5.8, 12.765
In 0.6 there is 1 digit after decimal.
In 5.8 there is 1 digit after decimal.
In 12.765 there are 3 digits after decimal.
12.765 contains 3 digits after decimal point so by changing 0.6 as 0.600 and 5.8 as 5.800
Hence, 0.600, 5.800 and 12.765 are like decimals.
(iv) 5.296, 5.2, 5.29
In 5.296 there are 3 digits after decimal.
In 5.2 there is 1 digit after decimal.
In 5.29 there are 2 digits after decimal.
5.296 contains 3 digits after decimal point so by changing 5.2 as 5.200 and 5.29 as 5.290
Hence, 5.296, 5.200 and 5.290 are like decimals.
(v) 4.3294, 43.29, 432.94
In 4.3294 there are 4 digits after decimal.
In 43.29 there are 2 digits after decimal.
In 432.94 there are 2 digits after decimal.
4.3294 contains 4 digits after decimal point so by changing 43.29 as 43.2900 and 432.94 as 432.9400
Hence, 4.3294, 43.2900 and 432.9400 are like decimals.
Exercise 7.8
Question 1: Find the sum in each of the following:
Question 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 2:
(i) 41.8, 39.24, 5.01 and 62.6
Change the given values in like fractions.
41.80 + 39.24 + 5.01 + 62.60 = 148.65
Hence, the addition of 41.8, 39.24, 5.01 and 62.6 is 148.65
(ii) 4.702, 4.2, 6.02 and 1.27
Change the given values in like fractions.
4.702 + 4.200 + 6.020 + 1.270 = 16.192
Hence, the addition of 4.702, 4.2, 6.02 and 1.27 is 16.192
(iii) 18.03, 146.3, 0.829 and 5.324
Change the given values in like fractions.
18.030 + 146.300 + 0.829 + 5.324 = 170.483
Hence, the addition of 18.03, 146.3, 0.829 and 5.324 is 170.483
Question 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 3:
(i) 0.007 + 8.5 + 30.08
Change the given values in like fractions.
0.007 + 8.500 + 30.080 = 38.587
Hence, the sum of 0.007 + 8.5 + 30.08 is 170.483
(ii) 280.69 + 25.2 + 38
Change the given values in like fractions.
280.69 + 25.20 + 38.00 = 343.89
Hence, the sum of 280.69 + 25.2 + 38 is 343.89
(iii) 25.65 + 9.005 + 3.7
Change the given values in like fractions.
25.650 + 9.005 + 3.700 = 38.355
Hence, the sum of 25.650 + 9.005 + 3.700 is 38.355
(iv) 27.076 + 0.55 + 0.004
Change the given values in like fractions.
27.076 + 0.550 + 0.004 = 27.630
Hence, the sum of 27.076 + 0.550 + 0.004 is 27.630
Question 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 4:
Radhika’s mother gave her = Rs 10.50
Radhika’s father gave her = Rs 15.80
Total amount given by her parents = Rs 10.50 + Rs 15.80 = Rs 26.30
Thus, the total amount given by her parents is Rs 26.30.
Question 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 5:
Apple’s weight bought by Rahul = 4 kg 90 g = 4.090 kg
Grapes weight bought by Rahul = 2 kg 60 g = 2.060 kg
Mangoes weight bought by Rahul = 5 kg 300 g = 5.300 kg
The weight of all the fruits = 4.090 + 2.060 + 5.300 = 11.450 kg
Hence, the total weight of the fruits is 11.450 kg.
Question 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 6:
Cloth bought for shirt = 3 m 20 cm = 3.20 m
Cloth bought for skirt = 2 m 50 cm = 2.05 m
Total cloth bought by her = 3.20 + 2.05 = 5.25 m = 5 m 25 cm
Thus, the total cloth bought by Nasreen is 5 m 25 cm.
Question 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 7:
Sunita travelled by bus = 15 km 268 m = 15.268 km
Sunita travelled by car = 7 km 7 m = 7.007 km
Sunita travelled by foot = 500 m = 0.500 km
The total distance from residence to school = 15.268 + 7.007 + 0.500 = 22.775 km
Thus, the distance from her residence to school is 22.775 km.
Exercise 7.9
Question 2: Find the value of:
(i) 9.756 – 6.28
(ii) 21.05 – 15.27
(iii) 18.5 – 6.79
(iv) 48.1 – 0.37
(v) 108.032 – 86.8
(vi) 91.001 – 72.9
(vii) 32.7 – 25.86
(viii) 100 – 26.32
Solution 2:
(i) 9.756 – 6.28
Change the given values in like fractions.
9.756 – 6.280 = 3.476
Hence, the value of given expiration is 3.476.
(ii) 21.05 – 15.27
Change the given values in like fractions.
21.05 – 15.27 = 5.78
Hence, the value of given expiration is 5.78.
(iii) 18.5 – 6.79
Change the given values in like fractions.
18.50 – 6.79 = 11.71
Hence, the value of given expiration is 11.71.
(iv) 48.1 – 0.37
Change the given values in like fractions.
48.10 – 0.37 = 47.73
Hence, the value of given expiration is 47.73.
(v) 108.032 – 86.8
Change the given values in like fractions.
108.032 – 86.800 = 21.232
Hence, the value of given expiration is 21.232.
(vi) 91.001 – 72.9
Change the given values in like fractions.
91.001 – 72.900 = 18.101
Hence, the value of given expiration is 18.101.
(vii) 32.7 – 25.86
Change the given values in like fractions.
32.70 – 25.86 = 6.84
Hence, the value of given expiration is 6.84.
(viii) 100 – 26.32
Change the given values in like fractions.
100 – 26.32 = 73.68
Hence, the value of given expiration is 73.68.
Question 3: The sum of two numbers is 100. If one of them is 78.01, find the other.
Solution 3:
Question 4: Waheeda’s school is at a distance of 5 km 350 m from her house. She travels 1 km 70 m on foot and the rest she travels by bus. How much distance does she travel by bus?
Solution 4:
Question 5: Raju bought a book for Rs 35.65. He gave Rs 50 to the shopkeeper. How much money did he get back from the shopkeeper?
Solution 5:
Total Amount given to shopkeeper = Rs. 50
Cost of book = Rs. 35.65
The remaining amount returned by shopkeeper = 50 – 35.65 = Rs 14.35
Thus, the remaining amount returned by the shopkeeper is Rs 14.35.
Question 6: Ruby bought a watermelon weighing 5 kg 200 g. Out of this she gave 2 kg 750 g to her neighbour. What is the weight of the watermelon left with Ruby?
Solution 6:
Watermelon weight bought by Ruby is = 5 kg 200 g = 5.200 kg
Watermelon weight Ruby gave to neighbour is = 2 kg 750 g = 2.750 kg
Weight of watermelon left with Ruby = 5.200 – 2.750 = 2.450 kg
Thus, the weight of watermelon left with Ruby is 2.450 kg.
Question 7: Victor drove 89.050 km on Saturday and 73.9 km on Sunday. How many kilometres more did he drive on Sunday?
Solution 7:
Distance travelled on Saturday = 89.050 km
Distance travelled on Sunday = 73.9 km
Distance travelled by Victor more on Saturday = 89.050 – 73.9 = 15.15 km
Thus, 15.15km more he drive on Sunday Victor
Question 8: Raju bought a book for Rs 35.65. He gave Rs 50 to the shopkeeper. How much money did he get back from the shopkeeper?