S.chand publication New Learning Composite mathematics solution of class 7 Chapter 2 Fractions and Decimals Exercise 2G

 Exercise 2G

Question 1

Write down as decimals.

(a) (i) 7 tenths

Sol :

(i) $\frac{7}{10}=0.7$

(ii) 8 hundredths

Sol :

(ii) $\frac{8}{100}=0.08$

(iii) 6 thousandths

Sol :

(iii) $\frac{6}{1000}=0.006$

(b)

(i) $\frac{6}{10}+\frac{8}{100}$

Sol :

$=\frac{60+8}{100}$

$=\frac{68}{100}$

=0.68

(ii) $\frac{3}{10}+\frac{5}{100}+\frac{8}{1000}$

$\frac{9}{10}+\frac{5}{100}+\frac{8}{1000}$

$=\frac{300+50+8}{1000}$

$=\frac{358}{1000}$

=0.358

(iii) $5+\frac{7}{10}$

Sol :

$=\frac{50+7}{10}=\frac{57}{10}$

=5.7

(iv) $20+7+\frac{8}{10}+\frac{5}{100}$

Sol :

$=\frac{2000+700+80+5}{100}=\frac{2785}{100}$

=27.85

(v) $800+5+\frac{3}{10}+\frac{5}{100}$

Sol :

$=\frac{80000+500+30+5}{100}$

$=\frac{80535}{100}$

=805.35

(vi) $2+\frac{5}{100}$

Sol :

$=\frac{200+5}{100}=\frac{205}{100}$

=2.05

(vii) $\frac{6}{10}+\frac{9}{1000}$

Sol :

$=\frac{600+9}{1000}=\frac{609}{1000}$

=0.609

(viii) $40+\frac{7}{100}+\frac{9}{10000}$

Sol :

$=\frac{400000+700+9}{10000}$

$=\frac{400709}{10000}$

=40.0709

Question 2

Write in expanded form :

(a) 3.59

$=3+\frac{5}{10}+\frac{9}{100}$

(b) 0.007

$=\frac{7}{1000}$

(c) 39.2307

$=3\times 10+9+\frac{2}{10}+\frac{3}{100}+\frac{7}{10000}$

$=30+9+\frac{2}{10}+\frac{3}{100}+\frac{7}{10000}$

(d) 8.075

$=8+\frac{7}{100}+\frac{5}{1000}$

Question 3

State the value of 7 in

(a) 73.89

Here, the value of 7

=7×10=70

(b) 69.71

Here, the value of

$7=\frac{7}{10}$

(c) 2.078

Here, the value of 7$=\frac{7}{100}$

(d) 6.0027

Here, the value of 7$=\frac{7}{10000}$

Question 4

Express as a fraction in simplest form :

(a) 9.08

$=\frac{908}{100}=\frac{227}{25}$

$=9\frac{2}{25}$

(b) 2.075

$=\frac{2075}{1000}$

$=2\frac{3}{40}$

(c) 0.018

$=\frac{18}{1000}=\frac{9}{500}$

(d) 1.032

$=\frac{1032}{1000}=\frac{129}{125}$ 

$=1\frac{4}{125}$

Question 5

Insert < , > or = to make each statement true.

(a) 3.703 < 3.730

(b) 1.402 > 1.4

(c) 9.37 = 9.370

(d) 0.407 > 0.0801

Question 6

Arrange in descending order :

(a) 0.02, 2.02, 0.20, 0.002, 2.002

(b) 652.12, 65.213, 65.135, 61.53

Sol :

(a) 2.02, 2.002, 0.20, 0.02, 0.002

(b) 652.12, 65.213, 65.135, 61.53

Question 7

Arrange in ascending order :

(a) 0.09, 0.1, 0.099, 1.001, 0.937

(b) 5.2, 5.02, 5.002, 5.19, 5.119, 5.219

Sol :

(a) 0.09, 0.099, 0.1, 0.937, 1.001

(b) 5.002, 5.02, 5.119, 5.19, 5.2, 5.219

Question 8

Convert into decimals

(a) $\frac{5}{16}$

Sol :

(a) $\frac{5}{16}=0.3125$

(b) $\frac{1}{8}$

Sol :

(b) $\frac{1}{8}=0.125$

(c) $\frac{1}{200}$

Sol :

(c) $\frac{1}{200}=0.005$

(d) $\frac{18}{25}$

Sol :

(d) $\frac{18}{25}=0.72$

Question 9

Find the sum.

(a) 31.826+3.471+0.004+45+0.6

$\begin{aligned}31.826 &\\3.471 &\\ 0.004 & \\ 45.000 & \\ (+)\phantom{00}0.600 &\\ \overline{80.901} &\end{aligned}$

(b) 72.9+2.3788+35.47+7806.3+0.379

$\begin{aligned}72.&9000\\2.&3788\\35.&4700\\7806.&3000\\(+)~~~0.&3790\\ \hline 7917.&4278\end{aligned}$

Question 10

Subtract :

(a) 890.89-8.9

$\begin{aligned}890.&89\\(-)\phantom{00}8.&90\\ \hline 881.&99\end{aligned}$

(b) 23-12.8765

$\begin{aligned}23.&0000\\(-)~~~12.&8765 \\ \hline 10.&1235\end{aligned}$