Can fractions be written with a one under them and can problems be solved this way

How would you write $\frac{a}{0.1}$?

Are either of these ways acceptable?

$\frac{\frac{a}{1}}{\frac{\frac{1}{10}}{1}}=\frac{a}{1}\times \frac{1}{\frac{1}{10}}$

or

$\frac{\frac{a}{1}}{\frac{1}{10}}=\frac{a}{1}\times \frac{10}{1}$

How would you write $\frac{a}{0.1}$?

Are either of these ways acceptable?

$\frac{\frac{a}{1}}{\frac{\frac{1}{10}}{1}}=\frac{a}{1}\times \frac{1}{\frac{1}{10}}$

or

$\frac{\frac{a}{1}}{\frac{1}{10}}=\frac{a}{1}\times \frac{10}{1}$