1. **State the problem:** Calculate the sum of the fractions $\frac{2}{5} + \frac{2}{4}$. 2. **Formula and rules:** To add fractions, find a common denominator, then add the numerators. 3. **Find the least common denominator (LCD):** The denominators are 5 and 4. The LCD is 20. 4. **Convert each fraction to have denominator 20:** $$\frac{2}{5} = \frac{2 \times 4}{5 \times 4} = \frac{8}{20}$$ $$\frac{2}{4} = \frac{2 \times 5}{4 \times 5} = \frac{10}{20}$$ 5. **Add the fractions:** $$\frac{8}{20} + \frac{10}{20} = \frac{8 + 10}{20} = \frac{18}{20}$$ 6. **Simplify the fraction:** $$\frac{18}{20} = \frac{\cancel{18}^{9}}{\cancel{20}^{10}} = \frac{9}{10}$$ **Final answer:** $$\frac{2}{5} + \frac{2}{4} = \frac{9}{10}$$