1. The problem is to find the sum of 10 and 10. 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: $10 + 10$. 4. Calculate the sum: $10 + 10 = 20$. 5. Therefore, the answer is 20.