To do this, first add the whole numbers: 8 + 3 = 11. Set that aside for a moment.
To add the fractions, 1/2 + 4/5, you need a common denominator. With 2 and 5, you’d have an LCD of 10.
1/2 = 5/10
4/5 = 8/10
So 1/2 + 4/5 = 5/10 + 8/10 = 13/10
Now, 13 is bigger than 10, so 13/10 is the same as 1 and 3/10.
We’ll add that to the 11 we found back in the beginning and get 11 + 1 and 3/10 = 12 and 3/10 or 12.3.