im in the interest of educating people not just giving them the answer so check it:
Think of your final yearly grade as 100 points. 10% of those points are the final so 10 points for final, 90 points for everything else.
your current percentage w/o final is 82 meaning 82 percent of possible points(90)
so 82 percent of 90 is .82*90 = 73.8 points.
Now, you want to get at least 80% of total points(100)
so 80 percent of 100 is .80*100 = 80 points.
meaning you only need to get 6.2 more points!
6.2 / 10 points possible = 62 Percent!!! Thats all you need!! I would thank your teacher. most finals are worth at least 35-40% of final grade.
now I hope you can use this wonderful fill to underachieve for the rest of your life!
Teach a man to fish...