By adding simple logic you can round off to single digit. In any value you add 0.05 and pick only one digit after the decimal and the result will be the value after rounding off in one decimal place.
5
6.4
there are no decimals to round off in 96.
To round off 3044.4498, you would look at the digit after the desired decimal place. In this case, the digit after the fourth decimal place is 9. Since 9 is greater than 5, you round up the fourth decimal place to get 3044.45.
3.91 rounded off to one decimal place = 3.9
37.7
61.6 is the answer
22.0
1.9
77.482
69.6
6.5km
7.2