To add the fractions $\frac{9}{10}$ and $\frac{5}{6}$, we need to find a common denominator.
The least common multiple of 10 and 6 is 30, so we can rewrite the fractions as $\frac{27}{30}$ and $\frac{25}{30}$.
Now, we can add the fractions: $\frac{27}{30} + \frac{25}{30} = \frac{52}{30}$.
To simplify the fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 2.
So, $\frac{52}{30}$ simplifies to $\frac{26}{15}$.
Therefore, the sum of $\frac{9}{10}$ and $\frac{5}{6}$ is $\boxed{\frac{26}{15}}$.The answer is: \frac{26}{15}
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Calculate the sum of $\frac{9}{10}$ and $\frac{5}{6}$ and express your answer as a fraction in simplest form.

### Answer:
