Anything fifteen minutes or greater and less than forty-five minutes rounds to the half hour. Anything forty-five minutes or greater and less than fifteen minutes rounds to the hour.
2:45 and 3:14 round to 3:00
3:15 and 3:44 round to 3:30
4.5 already is rounded to the nearest half.
To the nearest half, one half
1,500,000 is already rounded to the nearest half-million.
4/5 to the nearest half is 1.
It is 2.5
5.5
53
6.5
38.412 rounded to the nearest half is 38.5
12.5
Zero
1/2