99 deciliters in liters
Result
The conversion result is: 99 deciliters is equivalent to 9.9 liters.[1]
Conversion formula
How to convert 99 deciliters to liters?
We know (by definition) that: 1 dl ≈ 0.1 liter.
We can set up a proportion to solve for the number of liters.
1 dl / 99 dl ≈ 0.1 liter / x liter
Now, we cross multiply to solve for our unknown x:
x liter ≈ (99 dl / 1 dl) * 0.1 liter → x liter ≈ 9.9 liter
Conclusion:
99 dl ≈ 9.9 liter

Conversion in the opposite direction
The inverse of the conversion factor is that 1 liter is equal to 0.101010101010101 times 99 deciliters.
It can also be expressed as: 99 deciliters is equal to 1 / 0.101010101010101 liters.
Approximation
An approximate numerical result would be: ninety-nine deciliters is about zero liters, or alternatively, a liter is about zero point one zero times ninety-nine deciliters.
Footnotes
[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).
Results may contain small errors due to the use of floating point arithmetic.