Question: Express 0.09 as a fraction.
1. **State the problem:** We need to express the decimal $0.09$ as a fraction.
2. **Recall the rule:** Any decimal can be written as a fraction with a denominator that is a power of 10. Since $0.09$ has two decimal places, it can be written as $\frac{9}{100}$.
3. **Write the fraction:**
$$0.09 = \frac{9}{100}$$
4. **Simplify the fraction:** Find the greatest common divisor (GCD) of $9$ and $100$. The GCD is $1$, so the fraction is already in simplest form.
5. **Final answer:**
$$0.09 = \frac{9}{100}$$
**Note:** The answer $\frac{1}{9}$ given in the prompt is incorrect for $0.09$. The correct fraction is $\frac{9}{100}$.