First, change a fraction to share a common denominator.
1 2
-- = ---
2 4
Next, add the numerators but keep the denominators the same.
2 3 5
-- + -- = --
4 4 4
Since 4 goes into 5 one time, we have 1 full number. There is only 1/4 left over, so the answer is 1 and 1/4.