How do you convert $2$ liters to fluid ounces?

Hint: A liter is a unit of volume in the measurement system. A liter is defined as the volume of a cube that is 10 centimeters of a side. There are about $3.785$liters in a U.S. gallon
A U.S. fluid ounce is ${{\dfrac{1}{128}}^{th}}$of a U.S. gallon.

Complete step-by-step answer:
1 liter is equal to $33.814$fluid ounces. Since the value of fluid ounces in one liter is given to us, in order to find the value of fluid ounces in more than one liter we will simply use the unitary method concept. In such a method if the value of smaller quantity is provided to us and if we need to calculate the value of larger quantity then we simply perform the mathematical operation called multiplication. This gives the desired result of the question.

We know that
Fluid ounces present in $1$liters of fluid = $33.814$
Fluid ounces present in $2$liters of fluid can be calculated by unitary method, by simply multiplying the value to $2$ as depicted below
$\Rightarrow \,33.814\,\times \,2\,=\,67.628$ fluid ounces.
Therefore, $2$ liters of fluid contain$67.628$ fluid ounces.

Note: Always be careful while performing the conversion. The values of interconversions should be applied properly. The key mistake which is made while solving such questions is the basic mathematical operations. Make sure that the mathematical operation is performed correctly. Fluid ounces is a smaller quantity as compared to the liters. Therefore, a liter will have a much larger number of fluid ounces. You can recheck the answer using this comparison.