For hundreds like this, oftentimes it's quicker and more simple to think of it as just 100. The proportion from 100 to 500 is just 5. 16% of 100 is 16. So, multiply 16 * 5. You would get 80.
The second method is you can use 0.16 * 500. It's the more conventional method, and you get 80, like the last method.
