It isn't at all!
When dividing numbers, the easiest way is to imagine the values as a fraction, and then reduce that fraction. If it reduces to a core fraction (ones that you should know their decimal value without thinking), then you have your answer.
We simplified our fraction by dividing the numerator and denominator by 4, which left us with
, which we know is equal to
0.8.
You may be confused thinking that 0.8 is the same as 8. 0.8 is actually a tenth of the value of 8. This makes them very different values.
Below, I have also included a picture to help you memorize your common/core fractions. I recommend learning these as they will help you get through all sorts of math, from Geometry to Calculus!