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Decimals

Class 6th Mathematics CBSE Solution
Exercise 8.1
  1. Write the following as numbers in the given table: (a) (b) Hundreds (100) Tens…
  2. Write the following decimals in the place value table: (a) 19.4 (b) 0.3 (c) 10.6…
  3. (a) Seven-tenths (b) Two tens and nine-tenths (c) Fourteen point six (d) One…
  4. (a) 5/10 (b) 3 + 7/10 (c) 200+60+5 + 1/10 (d) 70 + 8/10 (e) 88/10 (f) 4 2/10 (g)…
  5. Write the following decimals as fractions. Reduce the fractions so obtained to…
  6. Express the following in cm, using decimals: (a) 2 mm (b) 30 mm (c) 116 mm (d) 4…
  7. Between which two consecutive whole numbers on the number line are the given…
  8. Show the following numbers on the number line: (a) 0.2 (b) 1.9 (c) 1.1 (d) 2.5…
  9. Write the decimal number represented the points A, B, C, D on the given number…
  10. The length of Rameshs notebook is 9 cm 5 mm. What will be its length in cm?…
  11. The length of a young gram plant is 65 mm. Express its length in cm.…
Exercise 8.2
  1. Complete the table with the help of these boxes and use decimals to write the…
  2. Write the numbers given in the following place value table in decimal form:…
  3. Write the following decimals in the place value table: (a) 0.29 (b) 2.08 (c)…
  4. Write each of the following as a decimal: (a) 20 + 9 + 4/10 + 1/100 (b) 137+…
  5. Write each of the following decimals in words: (a) 0.03 (b) 1.20 (c) 108.56 (d)…
  6. Between which two consecutive numbers upto tenths place on the number line does…
  7. Write as fractions in lowest terms: (a) 0.60 (b) 0.05 (c) 0.75 (d) 0.18 (e) 0.25…
Exercise 8.3
  1. Which is greater? (a) 0.3 or 0.4 (b) 0.07 or 0.02 (c) 3 or 0.8 (d) 0.5 or 0.05…
  2. Make five more examples and find the greater number from them.
Exercise 8.4
  1. Express as rupees using decimals: (a) 5 paise (b) 75 paise (c) 20 paise (d) 50…
  2. Express as metres using decimals: (a) 15 cm (b) 6 cm (c) 2 m 45 cm (d) 9 m 7 cm…
  3. Express as cm using decimals: (a) 5 mm (b) 60 mm (c) 164 mm (d) 9 cm 8 mm (e) 93…
  4. Express as km using decimals: (a) 8 m (b) 88 m (c) 8888 m (d) 70 km 5 m…
  5. Express as kg using decimals: (a) 2 g (b) 100 g (c) 3750 g (d) 5 kg 8 g (e) 26…
Exercise 8.5
  1. Find the sum in each of the following: (a) 0.07 + 8.5 + 30.08 (b) 15 + 0.632 +…
  2. Rashid spent Rs. 35.75 for Maths book and Rs. 32.60 for Science book. Find the…
  3. Radhikas mother gave her Rs. 10.50 and her father gave her Rs. 15.80. Find the…
  4. Nasreen bought 3 m 20 cm cloth for her shirt and 2 m 5 cm cloth for her…
  5. Naresh walked 2 km 35 m in the morning and 1 km 7 m in the evening. How much…
  6. Sunita travelled 15 km 268 m by bus, 7 km 7 m by car and 500 m on foot in order…
  7. Ravi purchased 5 kg 400 g rice, 2 kg 20 g sugar and 10 kg 850 g flour. Find the…
Exercise 8.6
  1. Subtract: (a) Rs. 18.25 from Rs. 20.75 (b) 202.54 m from 250 m (c) Rs. 5.36 from…
  2. Find the value of: (a) 9.756 - 6.28 (b) 21.05 - 15.27 (c) 18.5 - 6.79 (d) 11.6 -…
  3. Raju bought a book for Rs. 35.65. He gave a Rs. 50 note to the shopkeeper. How…
  4. Rani had Rs. 18.50. She bought one ice-cream for Rs. 11.75. How much money does…
  5. Tina had 20 m 5 cm long cloth. She cuts 4 m 50 cm length of cloth from this for…
  6. Namita travels 20 km 50 m everyday. Out of this, she travels 10 km 200 m by bus…
  7. Aakash bought vegetables weighing 10 kg. Out of this, 3 kg 500 g is onions, 2 kg…

Exercise 8.1
Question 1.

Write the following as numbers in the given table:

(a)

(b)


Answer:

We can write the numbers observing from the figure as below:


Question 2.

Write the following decimals in the place value table:

(a) 19.4 (b) 0.3 (c) 10.6 (d) 205.9


Answer:

The given numbers can be written in the form of place value table as follows:



Question 3.

Write each of the following as a decimal:

(a) Seven-tenths

(b) Two tens and nine-tenths

(c) Fourteen point six

(d) One hundred and two ones

(e) Six hundred point eight


Answer:

(a) Here,

We can write the given number into fraction as follows:


Seven-tenths =


Now,


According to the question,


This fraction can be converted in the form of decimal as follows:



(b) Here,


We can write the given numbers into fraction as follows:


Two tens = 20


And,


Nime-tenths =


It can together be written as


20 +



Now,


According to the question,


This fraction can be converted in the form of decimal as follows:



(c) We know that,


The given number cannot be written in the fraction form


But,


It is already written into decimal form.


Hence,


The given number can be directly written into the decimal format as below:


Fourteen point six = 14.6


(d) Here,


We know that,


The given number cannot be written in the fraction format


We can write the given numbers as follows:


On hundred = 100


And,


Two ones = 2


It can together be written as


100 + 2


= 102


Now,


According to the question,


This number can be converted in the form of decimal as follows:


102 = 102.0


(e) We know that,


The given number cannot be written in the fraction form


But,


It is already written into decimal form.


Hence,


The given number can be directly written into the decimal format as below:


Six hundred point eight = 600.8


Question 4.

Write each of the following as a decimal:

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)


Answer:

(a)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:



(b)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:




= 3.7


(c)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:




= 265.1


(d)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:




= 70.8


(e)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:



= 8.8


(f)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


At first,


We will convert the mixed fraction into improper fraction


=


=


As per the question,


The given fraction can be converted in the form of decimal as follows:



(g)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:


=



= 1 + 0.5


= 1.5


(h)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:



(i)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


As per the question,


The given fraction can be converted in the form of decimal as follows:


=



= 2 + 0.4


= 2.4


(j)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


At first,


We will convert the mixed fraction into improper fraction


=


=


As per the question,


The given fraction can be converted in the form of decimal as follows:



(k)


Here,


According to the question,


We have to convert the given fraction into decimal


Thus,


At first,


We will convert the mixed fraction into improper fraction


=


=


As per the question,


The given fraction can be converted in the form of decimal as follows:



Question 5.

Write the following decimals as fractions. Reduce the fractions so obtained to their lowest forms:

(a) 0.6 (b) 2.5

(c) 1.0 (d) 3.8

(e) 13.7 (f) 21.2

(g) 6.4


Answer:

(a) Here,

According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


0.6 =


Now,


According to the question,


We have to reduce the fractions to their lowest form as follows:



(b) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


2.5 =


Now,


According to the question,


We have to reduce the fractions to their lowest form as follows:



(c) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


1.0 =


Now,


According to the question,


We have to reduce the fractions to their lowest form


But,


We can observe that,


The fraction so obtained is already in its simplest form


(d) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


3.8 =


Now,


According to the question,


We have to reduce the fractions to their lowest form as follows:



(e) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


13.7 =


Now,


According to the question,


We have to reduce the fractions to their lowest form


But,


We can observe that,


The fraction so obtained is already in its simplest form


(f) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


21.2 =


Now,


According to the question,


We have to reduce the fractions to their lowest form as follows:



(g) Here,


According to the question,


At first,


We have to convert the given decimals into fractions


Thus,


6.4 =


Now,


According to the question,


We have to reduce the fractions to their lowest form as follows:




Question 6.

Express the following in cm, using decimals:

(a) 2 mm

(b) 30 mm

(c) 116 mm

(d) 4 cm 2 mm

(e) 162 mm

(f) 83 mm


Answer:

(a) 2 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


2mm =


= 0.2 cm


(b) 30 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


30mm =


= 3.0 cm


(c) 116 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


116mm =


= 11.6 cm


(d) 4 cm 2 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


4cm 2mm =


= 4.2 cm


(e) 162 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


162mm =


= 16.2 cm


(f) 83 mm


Here,


We have to convert the given quantity into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the given quantity into cm as follows:


83mm =


= 8.3 cm



Question 7.

Between which two consecutive whole numbers on the number line are the given numbers lie?

Which of these whole numbers is nearer the number?



(a) 0.8

(b) 5.1

(c) 2.6

(d) 6.4

(e) 9.1

(f) 4.9


Answer:

(a) Here,

We can clearly see that,


0.8 lie between 0 and 1.


And,


It is nearer to 1


(b) Here,


We can clearly see that,


5.1 lie between 5 and 6


And,


It is nearer to 5


(c) Here,


We can clearly see that,


2.6 lie between 2 and 3


And,


It is nearer to 3


(d) Here,


We can clearly see that,


6.4 lie between 6 and 7


And,


It is nearer to 6


(e) Here,


We can clearly see that,


9.1 lie between 9 and 10


And,


It is nearer to 9


(f) Here,


We can clearly see that,


4.9 lie between 4 and 5


And,


It is nearer to 5


Question 8.

Show the following numbers on the number line:

(a) 0.2

(b) 1.9

(c) 1.1

(d) 2.5


Answer:

(a) 0.2


Here,


We can see that,


On a number line 0.2 lies between 0 and 1


In such a way that the space between 0 and 1 is divided into 10 equal parts.


Hence,


We can obseve that each part will be equal to one-tenth.


Now,


0.2 is the second point between 0 and 1.



(b) 1.9


Here,


We can see that,


On a number line 1.9 lie between 1 and 2


In such a way that the space between 1 and 2 is divided into 10 equal parts.


Hence,


We can obseve that each part will be equal to one-tenth.


Now,


1.9 is the ninth point between 1 and 2.



(c) 1.1


Here,


We can see that,


On a number line 1.1 lies between 1 and 2


In such a way that the space between 1 and 2 is divided into 10 equal parts.


Hence,


We can obseve that each part will be equal to one-tenth.


Now,


1.1 is the second point between 1 and 2.



(d) 2.5


Here,


We can see that,


On a number line 2.5 lies between 2 and 3


In such a way that the space between 2 and 3 is divided into 10 equal parts.


Hence,


We can obseve that each part will be equal to one-tenth.


Now,


2.5 is the second point between 2 and 3.




Question 9.

Write the decimal number represented the points A, B, C, D on the given number line.



Answer:

Here,

We can observe that,


Point A on the number line represents 0.8


Point B on the number line represents 1.3


Point C on the number line represents 2.2


Point D on the number line represents 2.9



Question 10.

The length of Ramesh’s notebook is 9 cm 5 mm. What will be its length in cm?


Answer:

From the question, we have:

Length of the Ramesh’s notebook = 9cm 5mm


According to the question,


We have to convert the length into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the length of notebook into cm as follows:


9cm 5mm =


= 9.5 cm


Therefore,


Length of Ramesh’s notebook in cm = 9.5 cm



Question 11.

The length of a young gram plant is 65 mm. Express its length in cm.


Answer:

From the question, we have:

Length of the young gram plant = 65mm


According to the question,


We have to convert the length into cm


Now,


We know that,


1cm = 10mm


Hence,


We can convert the length of young gram plant into cm as follows:


65mm =


= 6.5 cm


Therefore,


Length of young gram plant in cm = 6.5cm




Exercise 8.2
Question 1.

Complete the table with the help of these boxes and use decimals to write the numbers:

(a)

(b)

(c)


Answer:

Here,

We can complete the table as follows:




Question 2.

Write the numbers given in the following place value table in decimal form:


Answer:

(a) Using the place value table,



We can write in decimal form as follows:


3


=


= 3.25


(b) Using the place value table,



We can write in decimal form as follows:


100


=


= 102.63


(c) Using the place value table,



We can write in decimal form as follows:


3


=


= 30.025


(d) Using the place value table,



We can write in decimal form as follows:


200


=


= 211.902


(e) Using the place value table,



We can write in decimal form as follows:


10


=


= 12.241


Question 3.

Write the following decimals in the place value table:

(a) 0.29

(b) 2.08

(c) 19.60

(d) 148.32

(e) 200.812


Answer:

(a) 0.29


Here,


We can write the decimal number in the form of place value table as follows:


0.29 = 0.2 + 0.09


=


(b) 2.08


Here,


We can write the decimal number in the form of place value table as follows:


2.08 = 2 + 0.08


=


(c) 19.60


Here,


We can write the decimal number in the form of place value table as follows:


19.60 = 10 + 9 + 0.60


=


(d) 148.32


Here,


We can write the decimal number in the form of place value table as follows:


148.32 = 148 + 0.32


=


(e) 200.812


Here,


We can write the decimal number in the form of place value table as follows:


200.812 = 200 + 0.8 + 0.01 + 0.002


=


Now,


We can write them in the place value table as follows:




Question 4.

Write each of the following as a decimal:

(a) 20 + 9 + +

(b) 137+

(c)

(d) 23 +

(e) 700+20+5+


Answer:

(a) Here,

We can write them in the form of decimals as follows:


20


=


= 29.41


(b) Here,


We can write them in the form of decimals as follows:


137


=


= 137.05


(c) Here,


We can write them in the form of decimals as follows:


=


= 0.764


(d) Here


We can write them in the form of decimals as follows:


23


=


= 23.206


(e) Here,


We can write them in the form of decimals as follows:


700


=


= 725.09



Question 5.

Write each of the following decimals in words:

(a) 0.03

(b) 1.20

(c) 108.56

(d) 10.07

(e) 0.032

(f) 5.008


Answer:

(a) Zero point zero three

(b) One point two zero


(c) One hundred eight point-five six


(d) Ten point zero seven


(e) Zero point zero three two


(f) Five point zero zero eight



Question 6.

Between which two consecutive numbers upto tenths place on the number line does each of the given numbers lie?

(a) 0.06

(b) 0.45

(c) 0.19

(d) 0.66

(e) 0.92

(f) 0.57


Answer:

(a) Here for 0.06

We can observe that,


The given decimal number lies between the following consecutive numbers up to ten place:


0.06 = 0 and 0.1


(b) Here for 0.45


We can observe that,


The given decimal number lies between the following consecutive numbers:


0.45 = 0.4 and 0.5


(c) Here for 0.19


We can observe that,


The given decimal number lies between the following consecutive numbers:


0.19 = 0.1 and 0.2


(d) Here for 0.66,


We can observe that,


The given decimal number lies between the following consecutive numbers:


0.66 = 0.6 and 0.7


(e) Here for 0.92


We can observe that,


The given decimal number lies between the following consecutive numbers:


0.92 = 0.9 and 1.0


(f) Here for 0.57,


We can observe that,


The given decimal number lies between the following consecutive numbers:


0.57 = 0.5 and 0.6


Question 7.

Write as fractions in lowest terms:

(a) 0.60

(b) 0.05

(c) 0.75

(d) 0.18

(e) 0.25

(f) 0.125

(g) 0.066


Answer:

(a) 0.60


Here,


The given fractions can be converted into their lowest fractions as follows:


0.60 =


=


=


(b) 0.05


Here,


The given fractions can be converted into their lowest fractions as follows:


0.05 =


=


(c) 0.75


Here,


The given fractions can be converted into their lowest fractions as follows:


0.75 =


=


(d) 0.18


Here,


The given fractions can be converted into their lowest fractions as follows:


0.18 =


=


(e) 0.25


Here,


The given fractions can be converted into their lowest fractions as follows:


0.25 =


=


(f) 0.125


Here,


The given fractions can be converted into their lowest fractions as follows:


0.125 =


=


(g) 0.066


Here,


The given fractions can be converted into their lowest fractions as follows:


0.066 =


=



Exercise 8.3
Question 1.

Which is greater?

(a) 0.3 or 0.4 (b) 0.07 or 0.02

(c) 3 or 0.8 (d) 0.5 or 0.05

(e) 1.23 or 1.2 (f) 0.099 or 0.19

(g) 1.5 or 1.50 (h) 1.431 or 1.490

(i) 3.3 or 3.300 (j) 5.64 or 5.603


Answer:

(a) In the above question,

The whole parts of both the numbers are same and the tenth part of 0.4 is greater than tenth part of 0.3


Hence,


0.4 > 0.3


(b) In the above question,


Both numbers have same parts upto the tenth place. Also, hundredth part of 0.07 is greater than that of hundredth part that of 0.02


Hence,


0.07 > 0.02


(c) In the above question,


It is clearly seen that whole part of 3 is greater than that of 0.8


Therefore,


3 > 0.8


(d) In the above question,


It is clearly seen that whole parts of these numbers are same. Also, tenth part of 0.5 is greater than that of 0.05


Therefore,


0.5 > 0.05


(e) In the above question,


Both the numbers have same parts upto tenth place but the hundredth part of 1.23 is greater than that of 1.20


Therefore,


1.23 > 1.20


(f) In the above question,


Both the numbers have same whole parts but the tenth part of 0.19 is greater than 0.099


Therefore,


0.099 < 0.19


(g) In the above question,


Both the numbers have same parts upto tenth place but there is no digit in the hundredth part of 1.5 which implies that the hundredth digit will be zero


Therefore,


1.5 = 1.50


(h) In the above question,


Both the numbers have same parts upto tenth place but the hundredth part of 1.490 is greater than that of 1.431


Therefore,


1.431 < 1.490


(i) In the above question,


Both the numbershave same parts upto tenth place but there is no digit in the hundredth and thousandth place of 3.3 which implies that these digits are 0 which are as same as that of 3.300


Therefore,


3.3 = 3.300


(j) In the above question,


Both the numbers have same parts up to the tenth place but the hundredth part of 5.64 is greater than that of 5.603


Therefore,


5.64 > 5.603



Question 2.

Make five more examples and find the greater number from them.


Answer:

(i) 0.5 or 0.8


In the above question,


The whole parts of both the numbers are same and the tenth part of 0.8 is greater than tenth part of 0.5


Hence,


0.5 < 0.8


(ii) 2.0 or 0.9


In the above question,


It is clearly seen that whole part of 2.0 is greater than that of 0.9


Therefore,


2.0 > 0.9


(iii) 0.042 or 0.22


In the above question,


Both the numbers have same whole parts but the tenth part of 0.22 is greater than 0.042


Therefore,


0.042 < 0.22


(iv) 3.012 or 2.99


In the above question,


It is clearly seen that whole part of 3.012 is greater than that of 2.99


Therefore,


3.012 > 2.99


(v) 0.055 or 0.15


In the above question,


Both the numbers have same whole parts but the tenth part of 0.15 is greater than 0.055


Therefore,


0.055 < 0.15




Exercise 8.4
Question 1.

Express as rupees using decimals:

(a) 5 paise

(b) 75 paise

(c) 20 paise

(d) 50 rupees 90 paise

(e) 725 paise


Answer:

(a) We know that,

100 Paise = 1 Rupee


Therefore,


5 Paise = Rupee


= 0.05 Rupee


(b) We know that,


100 Paise = 1 Rupee


Therefore,


75 Paise = Rupee


= 0.75 Rupee


(c) We know that,


100 Paise = 1 Rupee


Therefore,


20 Paise = Rupee


= 0.20 Rupee


(d) We know that,


100 Paise = 1 Rupee


Therefore,


50 Rupees 90 Paise = (50 + ) Rupees


= 50 + 0.90 Rupees


= 50.90 Rupees


(e) We know that,


100 Paise = 1 Rupee


Therefore,


725 Paise = Rupees


= 7.25 Rupees



Question 2.

Express as metres using decimals:

(a) 15 cm

(b) 6 cm

(c) 2 m 45 cm

(d) 9 m 7 cm

(e) 419 cm


Answer:

(a) We know that,

100 cm = 1 m


Therefore,


15 cm = m


= 0.15 m


(b) We know that,


100 cm = 1 m


Therefore,


6 cm = m


= 0.06 m


(c) We know that,


100 cm = 1 m


Therefore,


2 m 45 cm = (2 + ) m


= 2 + 0.45 m


= 2.45 m


(d) We know that,


100 cm = 1 m


Therefore,


9 m 7 cm = (9 + ) m


= 9 + 0.07 m


= 9.07 m


(e) We know that,


100 cm = 1 m


Therefore,


419 cm = m


= 4.19 m



Question 3.

Express as cm using decimals:

(a) 5 mm

(b) 60 mm

(c) 164 mm

(d) 9 cm 8 mm

(e) 93 mm


Answer:

(a) We know that,

10 mm = 1 cm


Therefore,


5 mm = cm


= 0.5 cm


(b) We know that,


10 mm = 1 cm


Therefore,


60 mm = cm


= 6 cm


(c) We know that,


10 mm = 1 cm


Therefore,


164 mm = cm


= 16.4 cm


(d) We know that,


10 mm = 1 cm


Therefore,


9 cm 8 mm = (9 + ) cm


= 9 + 0.8 cm


= 9.8 cm


(e) We know that,


10 mm = 1 cm


Therefore,


93 mm = cm


= 9.3 cm



Question 4.

Express as km using decimals:

(a) 8 m

(b) 88 m

(c) 8888 m

(d) 70 km 5 m


Answer:

(a) We know that,

1000 m = 1 km


Therefore,


8 m = km


= 0.008 km


(b) We know that,


1000 m = 1 km


Therefore,


88 m = km


= 0.088 km


(c) We know that,


1000 m = 1 km


Therefore,


8888 m = km


= 8.888 km


(d) We know that,


1000 m = 1 km


Therefore,


70 km 5 m = (70 + ) km


= 70 + 0.005 km


= 70.005 km



Question 5.

Express as kg using decimals:

(a) 2 g

(b) 100 g

(c) 3750 g

(d) 5 kg 8 g

(e) 26 kg 50 g


Answer:

(a) We know that,

1000 g = 1 kg
1 g =


Therefore,


2 g = kg


= 0.002 kg


(b) We know that,


1000 g = 1 kg


Therefore,


100 g = kg


= 0.1 kg


(c) We know that,


1000 g = 1 kg


Therefore,


3750 g = kg


= 3.750 kg


(d) We know that,


1000 g = 1 kg


Therefore,


5 kg 8 g = (5 + ) kg


= 5 + 0.008 kg


= 5.008 kg


(e) We know that,


1000 g = 1 kg


Therefore,


26 kg 50 g = (26 + ) kg


= 26 + 0.050 kg


= 26.050 kg



Exercise 8.5
Question 1.

Find the sum in each of the following:

(a) 0.07 + 8.5 + 30.08

(b) 15 + 0.632 + 13.8

(c) 27.076 + 0.55 + 0.004

(d) 25.65 + 9.005 + 3.7

(e) 0.75 + 10.425 + 2

(f) 280.69 + 25.2 + 38


Answer:

(a) We have to find out the sum for the following:

0.07 + 8.5 + 30.08



Therefore, sum is 38.587


(b) We have to find out the sum for the following:


15 + 0.632 + 13.8



Therefore, sum is 29.432


(c) We have to find out the sum for the following:


27.076 + 0.55 + 0.004



Therefore, sum is 27.630


(d) We have to find out the sum for the following:


25.65 + 9.005 + 3.7



Therefore, sum is 38.355


(e) We have to find out the sum for the following:


0.75 + 10.425 + 2



Therefore, sum is 13.175


(f) We have to find out the sum for the following:


280.69 + 25.2 + 38



Therefore, sum is 343.89



Question 2.

Rashid spent Rs. 35.75 for Maths book and Rs. 32.60 for Science book. Find the total amount spent by Rashid


Answer:

Given that,

Cost of Maths book = Rs. 35.75


Also,


Cost of Science book = Rs. 32.60


Therefore,


Total amount = 35.75 + 32.60



Hence, total amount spent by Rashid is Rs. 68.35



Question 3.

Radhika’s mother gave her Rs. 10.50 and her father gave her Rs. 15.80. Find the total amount given to Radhika by the parents


Answer:

Money gave by Mother = Rs. 10.50

Also,


Money Gave by Father = Rs. 15.80


Therefore,


Total money = 10.50 + 15.80



Hence, total money given by her parents = Rs. 26.30



Question 4.

Nasreen bought 3 m 20 cm cloth for her shirt and 2 m 5 cm cloth for her trousers. Find the total length of cloth bought by her


Answer:

Given that,

Cloth for shirt = 3 m 20 cm = 3.20 m


Also,


Cloth for trouser = 2 m 5 cm = 2.05 m


Therefore,


Total length of cloth = 3.20 + 2.05



Hence, total length of cloth = 5.25 m



Question 5.

Naresh walked 2 km 35 m in the morning and 1 km 7 m in the evening. How much distance did he walk in all?


Answer:

It is given in the question that,

Distance walked in the morning = 2 km 35 m


= (2 + ) km


= 2 + 0.035 km


= 2.035 km


Also,


Distance walked in the evening = 1 km 7 m


= (1 + ) km


= 1 + 0.007 km


= 1.007 km


Therefore,


Total Distance = 2.035 + 1.007



Hence, total distance walked by him = 3.042 km



Question 6.

Sunita travelled 15 km 268 m by bus, 7 km 7 m by car and 500 m on foot in order to reach her school. How far is her school from her residence?


Answer:

It is given in the question that,

Distance travelled by bus = 15 km 268 m


= (15 + ) km


= 15 + 0.268 km


= 15.268 km


Distance walked in the evening = 7 km 7 m


= (7 + ) km


= 7 + 0.007 km


= 7.007 km


Also,


Distance travelled by foot = 500 m


= km


= 0.500 km


Therefore,


Total Distance = 15.268 + 7.007 + 0.500



Hence, total distance of school from her residence = 22.775 km



Question 7.

Ravi purchased 5 kg 400 g rice, 2 kg 20 g sugar and 10 kg 850 g flour. Find the total weight of his purchases.


Answer:

Given in the question that,

Weight of rice = 5 kg 400 g


= (5 + ) kg


= 5 + 0.400 kg


= 5.400 kg


Weight of Sugar = 2 kg 20 g


= (2 + ) kg


= 2 + 0.020 kg


= 2.020 kg


Also,


Weight of flour = 10 kg 850 g


= (10 + ) kg


= 10 + 0.850


= 10.850 kg


Therefore,


Total weight = 5.400 + 2.020 + 10.850



Hence, total weight of purchases = 18.270 kg



Exercise 8.6
Question 1.

Subtract:

(a) Rs. 18.25 from Rs. 20.75

(b) 202.54 m from 250 m

(c) Rs. 5.36 from Rs. 8.40

(d) 2.051 km from 5.206 km

(e) 0.314 kg from 2.107 kg


Answer:

(a) We have to find out the difference for the following:

20.75 - 18.25



Therefore, difference is 2.50


(b) We have to find out the difference for the following:


250 - 202.54



Therefore, difference is 47.46


(c) We have to find out the difference for the following:


8.40 - 5.36



Therefore, difference is 3.04


(d) We have to find out the difference for the following:


5.206 - 2.051



Therefore, difference is 3.155


(e) We have to find out the difference for the following:


2.107 – 0.314



Therefore, difference is 1.793 kg



Question 2.

Find the value of:

(a) 9.756 – 6.28

(b) 21.05 – 15.27

(c) 18.5 – 6.79

(d) 11.6 – 9.847


Answer:

(a) Difference is as follows:

9.756 – 6.28



Therefore, difference is 3.476


(b) Difference is as follows:


21.05 – 15.27



Therefore, difference is 5.78


(c) Difference is as follows:


18.5 – 6.79



Therefore, difference is 11.71


(ds) Difference is as follows:


11.6 – 9.847



Therefore, difference is 1.753



Question 3.

Raju bought a book for Rs. 35.65. He gave a Rs. 50 note to the shopkeeper. How much money did he get back from the shopkeeper?


Answer:

It is given in the question that,

Cost of book = Rs. 35.65


Money given to seller = Rs. 50


Therefore,


Money that Raju will get back = Rs. 50 – Rs. 35.65



Therefore, he will get back Rs. 14.35



Question 4.

Rani had Rs. 18.50. She bought one ice-cream for Rs. 11.75. How much money does she have now?


Answer:

It is given in the question that.

Money spent by Rani on ice-cream = Rs. 11.75


Total money that Rani has = Rs. 18.50


Money left with Rani after buying an ice-cream = Rs. 18.50 – Rs. 11.75



Therefore, Rs. 6.75 left with Rani



Question 5.

Tina had 20 m 5 cm long cloth. She cuts 4 m 50 cm length of cloth from this for making a curtain. How much cloth is left with her?


Answer:

Total length of cloth = 20 m 5 cm = 20.05 m

Length if cloth cut to make curtain = 4 m 50 cm = 4.50 m

Therefore,

Length of cloth left with her = 20.05 – 4.50

Hence, 15.55 m length of cloth left with her


Question 6.

Namita travels 20 km 50 m everyday. Out of this, she travels 10 km 200 m by bus and the rest by auto. How much distance does she travel by auto?


Answer:

It is given in the question that,

Total distance travelled by Namita = 20 km 50 m = 20.050 km


Distance travelled by bus = 10 km 200 m = 10.200 km


Therefore,


Distance travelled by auto = Total distance – Distance travelled by bus


= 20.050 – 10.200



Hence, distance travelled by auto = 9.850 km



Question 7.

Aakash bought vegetables weighing 10 kg. Out of this, 3 kg 500 g is onions, 2 kg 75 g is tomatoes and the rest is potatoes. What is the weight of the potatoes?


Answer:

It is given in the question that,

Total weight of vegetables = 10 kg


Weight of onions = 3 kg 500 g

As 1 g = 1/1000 kg

500 g = 500/1000 kg

= 0.500 kg


3 kg 500 g = 3 + 0.500

= 3.500 kg


Weight of tomatoes = 2 kg 75 g

As 1 g = 1/1000 kg

500 g = 500/1000 kg

= 0.500 kg

2 kg 75 g = 2.075 kg

Therefore,


Weight of potatoes = Total weight – (Weight of onions + weight of tomatoes)


= 10.000 – (3.500 + 2.075)


= 10.000 – 5.575



Hence, weight of potatoes = 4.425 kg