How can we express 3.5 as a fraction?

To express 3.5 as a fraction, we can follow these steps:

1. First, recognize that 3.5 can be separated into its integer and decimal parts:

   3.5 = 3 + 0.5

2. Next, convert the decimal part (0.5) into a fraction. The decimal 0.5 is equal to:

   0.5 = \frac{5}{10} = \frac{1}{2} (after simplifying)

3. Now, we can combine the integer 3 with the fraction we derived from the decimal:

   3 = \frac{3}{1}

4. To add the fraction to the whole number, we need a common denominator. The whole number 3 can be rewritten as a fraction with a denominator of 2:

   3 = \frac{3 \times 2}{1 \times 2} = \frac{6}{2}

5. Now we can add the two fractions:

   \frac{6}{2} + \frac{1}{2} = \frac{6 + 1}{2} = \frac{7}{2}

Therefore, 3.5 expressed as a fraction is:

\frac{7}{2}

This means that 3.5 is equivalent to the fraction 7/2.