Complete the Decimal Expression: 2.4 = ?

To convert the decimal $2.4$ into a mixed number, we'll follow these steps:

• Step 1: Convert the decimal part $0.4$ into a fraction.
• Step 2: Simplify the fraction.
• Step 3: Combine with the whole number.

Let's work through each step:
Step 1: Recognize that $0.4$ means $\frac{4}{10}$ because there is one digit after the decimal point, placing it into tenths.
Step 2: Simplify $\frac{4}{10}$ by dividing both the numerator and denominator by their GCD, which is 2. This gives us $\frac{2}{5}$.
Step 3: Combine the whole number $2$ with the fraction $\frac{2}{5}$ to form the mixed number $2\frac{2}{5}$.

Therefore, the conversion of $2.4$ to a mixed number is $2\frac{2}{5}$.