#### Answer

$\frac{6}{5}$

#### Work Step by Step

We take the unknown number as $x$.
Five times the unknown number is $5x$.
$2$ subtracted from five times a certain number means $5x-2$.
Since when 2 is subtracted from five times a certain number, the result is 4, we write the equation $5x-2=4$.
Next, we solve this equation:
$5x-2=4$
$5x=4+2$
$5x=6$
$x=\frac{6}{5}$
Therefore, the unknown number is $\frac{6}{5}$.