859.867
The hundredth digit is the 6.
The digit after the 6 is the digit 7, since the digit 7 is more than 5, we round up the 6 to 7.
So it is ≈ 859.87
If the digit after the 6 was less than 5, we would have rounded down to 859.86
So 859.867 ≈ 859.87 to the nearest hundred digit
Hope this helps.