Round 81.139 to the nearest tenth

If the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up (+1).

If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down (no change).

81.139 ≈ 81.1

The first place after the decimal place is the tenth's place, then next is the hundreth's and so on

when rounding, if the number is 5 or more then round up , if less than 5, round down
exg\
.5 runded up=1
.4 rounded would be 0

so 81.139
disregard the 9
81.13
3 is less than 5
81.10