Actually the answer is 8.2
When rounding numbers, look for the number they are asking you to round to the nearest. In this case it's the tenths place.
8.246 the 2 is in the tenths place. Look at the number to the right of the 2.
8.246 the 4 is less than 5 so you have to round down. So therefore your answer is 8.2
Hope this helps. :)