1. **State the problem:** Calculate the sum of 5 and 5. 2. **Formula used:** Addition of two numbers is given by $a + b$. 3. **Apply the formula:** Here, $a = 5$ and $b = 5$, so we calculate $5 + 5$. 4. **Perform the addition:** $5 + 5 = 10$. 5. **Final answer:** The sum of 5 and 5 is **10**.