A baker says a recipe needs 'about 300 grams' of sugar instead of the exact '304 grams'. What is the best reason for doing this?

To make the measurement more precise.

Because rounded numbers are simpler to remember and communicate.

In which of these situations would using a rounded number be LEAST appropriate?

Telling a friend the population of a city.

Estimating the time needed for a road trip.

Entering your Personal Identification Number (PIN) at an ATM.

Guessing the number of jellybeans in a large jar.