5.3 Real-world calculations

With real-world calculations you really have to think about what you are doing.
What are you calculation? Do you need to round your answer, and how do you need to round it up of down? You can't have half a person.

To really learn how to do real-world calculations you need to make a lot of exercises and practice.

Make sure you read theory A and B of paragraph 5.3 in your book