plus indicates that it is a sum (not a difference): 1/4 + 2/4 = 3/4. You can just add the numerators, since the denominators are the same.
1/8 plus 1/4 plus 1/2 = 7/8 or 0.875
1
the sum would be 1/4 + 3/5 = 5/20 + 12/20 = 17/20
((2 plus (1 over 4)) plus 3) plus (7 over 8) = 6.12500
1 and 1 over 20
28
2 over 3 plus 4 1 over 4 = 59/12 or 411/12
2 & 1 over 4 (2.25)
1 and 4 5ths
The commutative property of addition.
I believe 7/8 would be a good answer