The hundredths place is the second digit after the decimal point. It is the 6 in this case.
Since the next digit (3) is 4 or less, the hundredths place stays the same and the rest is basically just cut off, leaving 0.86.
If the next digit (3) were 5 or more, the hundredths place would have gone up 1 (to 7) and the rest would have been cut off, giving a final result of 0.87
