When do you round a whole number?

Answer 1

It depends what place value you are rounding by. Once you have determined which value you are doing you round up if it is 5 or more and round down if it is 4 or less. For example 6.5 would be rounded to 7 and 14.3 would be rounded down to 14.

Answer 2

Whenever the representation of a whole number would be necessary to fulfill a logical outcome. If you calculate the amount of drinks needed for a party and you come out to 147.243, you're not going to reasonably make .243ths glass. Feasibly, you'd be better off not making that additional drink vs. making it. Thus you need 147 glasses. Some, however, would prefer to make the 148th glass, just-in-case.

Answer 3

When you are asked to and also when a fraction does not make sense. For example, if a school wants to hire buses to take a group of 60 children and staff on a trip and each coach can take 50 passengers, the mathematics will tell you that 1.2 buses are needed. But you cannot hire a fraction of a bus so you must round UP to 2 buses.