1. The problem is to find the sum of 136.168 and 272.16. 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 given values: $$136.168 + 272.16$$ 4. Align the decimal points and add: $$136.168 + 272.160 = 408.328$$ 5. Therefore, the sum of 136.168 and 272.16 is: $$\boxed{408.328}$$