Decimals - Exercise 3(B)

Add:

9.67, 15.98

Answer

The maximum number of decimal places is 2. The numbers are already like decimals.

On adding column-wise, we get:

$\begin{array}{r} 9.67 \\ +\phantom{0}15.98 \\ \hline 25.65 \\ \hline \end{array}$

Hence, the sum is 25.65

Add:

6.9, 23.84

Answer

Maximum number of decimal places in given decimals is 2. So, we convert them into like decimals, each having 2 places of decimal, by annexing zeros.

$\begin{array}{r} 6.90 \\ +\phantom{0}23.84 \\ \hline 30.74 \\ \hline \end{array}$

Hence, the sum is 30.74

Add:

35.67, 18.794, 4.9, 31.82

Answer

Maximum number of decimal places in given decimals is 3. So, we convert them into like decimals, each having 3 places of decimal, by annexing zeros.

Thus, we get: 35.670, 18.794, 4.900 and 31.820

On adding column-wise, we get:

$\begin{array}{r} 35.670 \\ 18.794 \\ 4.900 \\ +\phantom{0}31.820 \\ \hline 91.184 \\ \hline \end{array}$

Hence, the sum is 91.184

Add:

63.05, 24.839, 3.7, 16.85

Answer

Maximum number of decimal places in given decimals is 3. So, we convert them into like decimals, each having 3 places of decimal, by annexing zeros.

Thus, we get: 63.050, 24.839, 3.700 and 16.850

On adding column-wise, we get:

$\begin{array}{r} 63.050 \\ 24.839 \\ 3.700 \\ +\phantom{0}16.850 \\ \hline 108.439 \\ \hline \end{array}$

Hence, the sum is 108.439

Subtract :

2.975 from 8.23

Answer

Converting the given decimals into like decimals, we have to subtract 2.975 from 8.230.

Subtracting columnwise, we get:

$\begin{array}{r} 8.230 \\ -\phantom{0}2.975 \\ \hline 5.255 \\ \hline \end{array}$

Hence, the answer is 5.255

Subtract :

0.75 from 1.3

Answer

Converting the given decimals into like decimals, we have to subtract 0.75 from 1.30.

Subtracting columnwise, we get:

$\begin{array}{r} 1.30 \\ -\phantom{0}0.75 \\ \hline 0.55 \\ \hline \end{array}$

Hence, the answer is 0.55

Subtract :

6.054 from 11.26

Answer

Converting the given decimals into like decimals, we have to subtract 6.054 from 11.260.

Subtracting columnwise, we get:

$\begin{array}{r} 11.260 \\ -\phantom{0}6.054 \\ \hline 5.206 \\ \hline \end{array}$

Hence, the answer is 5.206

Subtract :

134.68 from 201.3

Answer

Converting the given decimals into like decimals, we have to subtract 134.68 from 201.30.

Subtracting columnwise, we get:

$\begin{array}{r} 201.30 \\ -134.68 \\ \hline 66.62 \\ \hline \end{array}$

Hence, the answer is 66.62

Take out 6.345 from 8.1.

Answer

Converting the given decimals into like decimals, we have to subtract 6.345 from 8.100.

Subtracting columnwise, we get:

$\begin{array}{r} 8.100 \\ -\phantom{0}6.345 \\ \hline 1.755 \\ \hline \end{array}$

Hence, the answer is 1.755

What is the difference between 68.5 and 0.685?

Answer

Converting the given decimals into like decimals, we have to subtract 0.685 from 68.500.

Subtracting columnwise, we get:

$\begin{array}{r} 68.500 \\ -\phantom{0}0.685 \\ \hline 67.815 \\ \hline \end{array}$

Hence, the answer is 67.815

What is the excess of 90 over 53.865?

Answer

Converting the given decimals into like decimals, we have to subtract 53.865 from 90.000.

Subtracting columnwise, we get:

$\begin{array}{r} 90.000 \\ -53.865 \\ \hline 36.135 \\ \hline \end{array}$

Hence, the answer is 36.135

What should be subtracted from 50 to get 34.57?

Answer

Let the required number be x

50 - x = 34.57

x = 50 - 34.57

Converting the given decimals into like decimals, we have to subtract 34.57 from 50.00.

Subtracting columnwise, we get:

$\begin{array}{r} 50.00 \\ -34.57 \\ \hline 15.43 \\ \hline \end{array}$

Hence, the answer is 15.43

What should be added to 63.47 to get 91?

Answer

Let the required number be x

63.47 + x = 91

x = 91 - 63.47

Converting the given decimals into like decimals, we have to subtract 63.47 from 91.00.

Subtracting columnwise, we get:

$\begin{array}{r} 91.00 \\ -63.47 \\ \hline 27.53 \\ \hline \end{array}$

Hence, the answer is 27.53

Manish buys a ₹8.75 metro ticket with a ₹20 note. How much money does he get back?

Answer

Given:

Total money = ₹20.00

Cost of ticket = ₹8.75

Money received back = ?

∴ Money received back = (Total money) - (Cost of ticket)

Substituting the values in above, we get:

Money received back = ₹20.00 - ₹8.75

Converting the given decimals into like decimals, we have to subtract 8.75 from 20.00.

Subtracting columnwise, we get:

$\begin{array}{r} 20.00 \\ -\phantom{0}8.75 \\ \hline 11.25 \\ \hline \end{array}$

Hence, he gets back ₹11.25

A baby increases in weight from 5.58 kg to 6.16 kg. How much weight has the baby gained?

Answer

Given:

New weight = 6.16 kg

Previous weight = 5.58 kg

Weight gained = ?

∴ Weight gained = (New weight) - (Previous weight)

Substituting the values in above, we get:

Weight gained = 6.16 kg - 5.58 kg

Subtracting columnwise, we get:

$\begin{array}{r} 6.16 \\ -5.58 \\ \hline 0.58 \\ \hline \end{array}$

Hence, the baby has gained 0.58 kg

Simplify :

67 + 13.85 - 29.904

Answer

Given expression:

= 67 + 13.85 - 29.904
= 67.000 + 13.850 - 29.904 $\quad$ [Converting into like decimals]
= (67.000 + 13.850) - 29.904
= 80.850 - 29.904
= 50.546

$\begin{array}{r|r} 67.000 & 80.850 \\ +\phantom{0}13.850 & -\phantom{0}29.904 \\ \hline 80.850 & 50.946 \\ \hline \end{array}$

Hence, the answer is 50.946

Simplify :

16.753 + 4.06 - 13.89

Answer

Given expression:

= 16.753 + 4.06 - 13.89
= 16.753 + 4.060 - 13.890 $\quad$ [Converting into like decimals]
= (16.753 + 4.060) - 13.890
= 20.813 - 13.890
= 6.923

$\begin{array}{r|r} 16.753 & 20.813 \\ +\phantom{0}4.060 & -\phantom{0}13.890 \\ \hline 20.813 & 6.923 \\ \hline \end{array}$

Hence, the answer is 6.923

Simplify :

1 - 10.5 + 12.213

Answer

Given expression:

= 1 - 10.5 + 12.213
= 1.000 - 10.500 + 12.213 $\quad$ [Converting into like decimals]
= (1.000 + 12.213) - 10.500 $\quad$ [Rearranging terms]
= 13.213 - 10.500
= 2.713

$\begin{array}{r|r} 1.000 & 13.213 \\ +\phantom{0}12.213 & -\phantom{0}10.500 \\ \hline 13.213 & 2.713 \\ \hline \end{array}$

Hence, the answer is 2.713

Simplify :

81 - 15.68 - 4.2

Answer

Given expression:

= 81 - 15.68 - 4.2
= 81.00 - 15.68 - 4.20 $\quad$ [Converting into like decimals]
= (81.00) - (15.68 + 4.20) $\quad$ [Rearranging terms]
= 81.00 - 19.88
= 61.12

$\begin{array}{r|r} 15.68 & 81.00 \\ +\phantom{0}4.20 & -\phantom{0}19.88 \\ \hline 19.88 & 61.12 \\ \hline \end{array}$

Hence, the answer is 61.12

Simplify :

555 - 55.5 - 5.555

Answer

Given expression:

= 555 - 55.5 - 5.555
= 555.000 - 55.500 - 5.555 $\quad$ [Converting into like decimals]
= 555.000 - (55.500 + 5.555) $\quad$ [Rearranging terms]
= 555.000 - 61.055
= 493.945

$\begin{array}{r|r} 55.500 & 555.000 \\ +\phantom{0}5.555 & -\phantom{0}61.055 \\ \hline 61.055 & 493.945 \\ \hline \end{array}$

Hence, the answer is 493.945

Simplify :

100 - 32.5 - 46.74 - 12.925

Answer

Given expression:

= 100 - 32.5 - 46.74 - 12.925
= 100.000 - 32.500 - 46.740 - 12.925 $\quad$ [Converting into like decimals]
= 100.000 - (32.500 + 46.740 + 12.925) $\quad$ [Rearranging terms]
= 100.000 - 92.165
= 7.835

$\begin{array}{r|r|r} 32.500 & 79.240 & 100.000 \\ +\phantom{0}46.740 & +\phantom{0}12.925 & -\phantom{0}92.165 \\ \hline 79.240 & 92.165 & \phantom{0}7.835 \\ \hline \end{array}$

Hence, the answer is 7.835