1. The problem asks to write the fraction $\frac{5}{6}$ as a whole number. 2. A fraction represents a part of a whole. To write a fraction as a whole number, the numerator must be divisible by the denominator. 3. Here, the numerator is 5 and the denominator is 6. 4. Since 5 is less than 6 and 6 does not divide 5 evenly, $\frac{5}{6}$ cannot be written as a whole number. 5. Therefore, $\frac{5}{6}$ is already in its simplest fractional form and is less than 1. 6. The final answer is that $\frac{5}{6}$ is not a whole number; it is a proper fraction.