To convert $2.009$ to a fraction:

1. Write $2.009$ as a fraction: $2.009 = \frac{2009}{1000}$

2. Simplify the fraction by finding the greatest common divisor (GCD) of 2009 and 1000. The GCD is 1, so the fraction is already in its simplest form: $\frac{2009}{1000}$

Thus, $2.009$ as a fraction is: $2.009 = \frac{2009}{1000}$

Would you like further details or have any questions?

Here are five related questions:

1. How do you simplify fractions?
2. What is a decimal expansion of a fraction?
3. How do you convert repeating decimals to fractions?
4. Can every decimal be converted into a fraction?
5. How do you find the GCD of two numbers?

Tip: Always check if a fraction can be simplified by dividing both the numerator and denominator by their GCD.