# Question 804b8

Nov 16, 2017

Let, the blank number be $x$
Then,
$\frac{8}{10} + x = 1$
Note- 1 can also be written as $\frac{1}{1} , \frac{2}{2} , \frac{3}{3} , \ldots . . , \frac{10}{10}$
Using that
$\frac{8}{10} + x = \frac{10}{10}$
Subtract $\frac{8}{10}$ from both sides
$\cancel{\frac{8}{10}} \cancel{+ \frac{8}{10}} + x = \frac{10}{10} - \frac{8}{10}$
$x = \frac{10 - 8}{10}$
Solve
$x = \frac{2}{10}$
Simplify
x=(cancel2^1)/(cancel(10^5)#
$x = \frac{1}{5}$