2565 is only 35 less than 2600 but it is 65 more than 2500 so the nearest 100 is 2600.
It is 39,600
It is: 4200
203 rounded to the nearest 100 is 200.
33.0
0.1
686000
70
200
6.24
It is: 100.0 and not 99.9
3
25.9 is already expressed to the nearest tenth.