What is 3.1 rounded to the nearest whole number

To do this you have to round the 3. It is the same things as asking to round to the ones place.

To the right of the 3, is a 1. Since this digit is not bigger than a 5, the 3 stays the same.

Your answer is 3

3, anything under. 5 is the same number. if its 5 and above the next number up