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".
The first figure to be discarded is 8 and as this is 5 or more then the previous figure (7) is increased by 1 and becomes 8.
65.78 rounded to the nearest tenth is 65.8
It is 232.4 when rounded to the nearest tenth
It is then 20.2 when rounded to the nearest tenth
10.5
33.8
45.1
6580
It is then 52.8 when rounded to the nearest tenth
It is then 56.5 when rounded to the nearest tenth
It is 232.4 when rounded to the nearest tenth
It is then 20.2 when rounded to the nearest tenth
It is 0.8 when rounded to the nearest tenth
4.4
10775.9
2.7
54.4
28.6
965.4