In order to round to the nearest tenth you need to look to the right and see the number next to the tenths, it will be the place of the hundredths
if in the hundredths place we have a 5 or more, the tenths digit will increase by one
if in the hundredths place we have a digit less than 4 the tenths remained with the same digit
For example
Rounded to the nearest tenth is 1.8
Another example
Round to the nearest tenth is 3.4