What is 98.155 rounded to the nearest tenth

If you want to round 98.155 to the nearest tenth, it is 98.2.
The 1 is in the tenths place.  
If the number to the right of it is 5 or more, round up.
If the number to the right of it is 4 or less, round down.
In this case, you round the digit in the tenths place up because the digit in the hundredths place is 5+.

The tenth is the first decimal place. When rounding you check if the number before is greater than 5, if it is you add 1 to the previous number, else you leave it as it is.

98.155 = 98.2(Rounded)

Hope this helps! :)