1. The problem is to find the sum of 6 and 7. 2. The formula for addition is $a + b = c$, where $a$ and $b$ are the numbers to add, and $c$ is the result. 3. Substitute the values: $6 + 7$. 4. Calculate the sum: $6 + 7 = 13$. 5. Therefore, the answer is 13.