It is 0.0 : the zero after the decimal point is an indication that the number is rounded to the nearest tenth.
The thousandths place is the third digit after the decimal point. 86.255 only has 3 digits after the decimal point so it is already (possibly) rounded to the nearest thousandth.
6.666
7.6
0.2
0.04
The decimal 82.2 is 82 when rounded to the nearest point.
132.7
2.6
26.1
There is no such thing as the nearest decimal point - since there is only one decimal point. To the nearest whole number, the value is 3.
Any decimal less than one will round to zero.
34.67, rounded to the nearest decimal point, is 34.7.
863.00
It is 0.0 : the zero after the decimal point is an indication that the number is rounded to the nearest tenth.
2.75590551 rounded to the nearest tenths (its one place after the decimal point) is 2.8.
The thousandths place is the third digit after the decimal point. 86.255 only has 3 digits after the decimal point so it is already (possibly) rounded to the nearest thousandth.