To express 2.5 as a fraction:

1. Write 2.5 as $\frac{2.5}{1}$.
2. Multiply both the numerator and the denominator by 10 to eliminate the decimal: $\frac{2.5 \times 10}{1 \times 10} = \frac{25}{10}.$
3. Simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 5: $\frac{25 \div 5}{10 \div 5} = \frac{5}{2}.$

So, $2.5$ as a fraction is $\frac{5}{2}$.

Would you like a more detailed explanation or have any other questions?

Here are 5 related questions:

1. How do you convert a decimal to a fraction?
2. What is the fraction form of 3.75?
3. How do you simplify fractions?
4. What are improper fractions and mixed numbers?
5. How do you convert a fraction to a decimal?

Tip: Always simplify a fraction by dividing both the numerator and denominator by their greatest common divisor (GCD).