The rule when rounding off numbers is "If the first figure to be discarded is 5 or more then the previous figure is increased by 1".
Regard the number under consideration as 059. As '5' is the first figure to be discarded and this is 5 (or more), then the previous figure (0) is increased by 1.
59 rounded to the nearest hundred is 100.
100
It is 300 when rounded to the nearest hundred
916 rounded to the nearest hundred is 900
0
It is already rounded to the nearest hundred thousandths. Rounded to the nearest thousands would be 87.381.
0
10000
0
0
678 is rounded nearest hundred is 700
10900
500