Exercise 3C
Q1 | Ex-3C | Class 8 | Decimals |S.Chand | Composite Mathematics | Chapter 3 | myhelper
Question 1
(i) 8.45÷10
Sol :$=\frac{845}{10}\times \frac{1}{10}=\frac{845}{100}$
Sol :
=0.845
(ii) 39÷10
$=\frac{39}{10}$
=3.9
(iii) 0.039÷10
Sol :
$=\frac{39}{1000}\times \frac{1}{10}$
=0.0039
(iv) 15.9÷10
Sol :
=1.59
(v) 537÷100
Sol :
=5.37
(vi) 9.7÷100
Sol :
=0.097
(vii) 76÷1000
Sol :
=0.076
(viii) 80÷10000
Sol :
=0.0080
Q2 | Ex-3C | Class 8 | Decimals |S.Chand | Composite Mathematics | Chapter 3 | myhelper
Question 2
(i) 0.6÷2
Sol :
=0.3
(ii) 29.4÷7
Sol :
=4.2
(iii) 0.063÷3
Sol :
=0.021
(iv) 1.232÷4
Sol :
=0.308
(v) 0.00037÷5
Sol :
=0.000074
(vi) 1026.76÷38
Sol :
=27.02
(vii) 20.202÷74
Sol :
=0.273
(viii) 11.2575÷114
Sol :
=0.09875
Q3 | Ex-3C | Class 8 | Decimals |S.Chand | Composite Mathematics | Chapter 3 | myhelper
Question 3
Divide :-
(i) 0.0000684 by 0.04
Sol :
$=\frac{684}{10000000}\div \frac{4}{100}=\frac{684}{100000}\times \frac{1}{4}$
$=\frac{171}{100000}$
=0.00171
(ii) 315.84 by 4.7
Sol :
$=\frac{31584}{100} \div \frac{47}{10}=\frac{31584}{10} \times \frac{1}{47}$
$=\frac{672}{10}$
=67.2
(iii) 3.154 by 1.25
Sol :
$=\frac{3154}{1000}\div \frac{125}{100}=\frac{3154}{1000}\times \frac{100}{125}$
$=\frac{3154}{10}\times \frac{1}{125}$
=2.5232
(iv) 0.79765 by 3.71
Sol :
$=\frac{79765}{100000} \div \frac{371}{100}=\frac{79765}{100000} \times \frac{100}{371}$
$=\frac{79765}{1000} \times \frac{1}{371}$
$=\frac{215}{1000}$
=0.215
(v) 18.21 by 0.003
Sol :
$=\frac{1821}{100} \div \frac{3}{1000}=\frac{1821}{100} \times \frac{1000}{3}$
$=\frac{607}{1} \times \frac{10}{1}$
=6070
(vi) 543.213 by 3.1
Sol :
$=\frac{543213}{1000} \div \frac{31}{10}=\frac{543213}{100} \times \frac{1}{31}$
$=\frac{17,523}{100}$
=175.23
(vii) 15.3 by 0.00017
Sol :
$=\frac{153}{10} \div \frac{17}{100000}=\frac{153}{1} \times \frac{17}{10000}$
=9×10000
=90000
Q4 | Ex-3C | Class 8 | Decimals |S.Chand | Composite Mathematics | Chapter 3 | myhelper
Question 4
Calculate , giving your answer correct to the individual number of decimal place:
(i) 0.754÷3 to 1 decimal place
Sol :
0.251≅0.3
(ii) 24.71÷13 to 3 decimal place
Sol :
=1.900
(iii) 16.7÷6 to 2 decimal place
Sol :
2.783≅2.78
(iv) 84÷0.7 to 3 decimal place
Sol :
$=\frac{84}{0.7} \times \frac{10}{10}=\frac{840}{7}$
=120
Q5 | Ex-3C | Class 8 | Decimals |S.Chand | Composite Mathematics | Chapter 3 | myhelper
Question 5
Give the following fractions as decimal correct to 3 decimal places:
(i) $\frac{1}{6}$
Sol :
0.166
(ii) $\frac{3}{11}$
Sol :
0.272
(iii) $\frac{7}{18}$
Sol :
(iv) $\frac{8}{55}$
Sol :
(v) $\frac{19}{24}$
Sol :
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