In adding fractions the denominators (the numbers below the line) have to be the same, so we need to make 1/4 into ?/8
To do this we need to multiply the 4 by 2, so we must do the same to the numerator (the number above the line), in this case, the 1
So 1/4 = 2/8
Now we can add the 2/8 + 3/8 and we get 5/8.
As 5 and 8 don't share any factors, this fraction cannot be simplified any further, and is the answer.