To round to the tenths place, you are trying to make the number enda tthe tenths place.
You are rounding the 9 in the tenths place, so look at the hundredths place. Since 8 is larger than 5, round the 9 up to 10.
We can't write 7.10 because that is a different number, so add the 1 to the 7 to get 8.
The final answer would be 8.0 or just 8.