Alright, this is my first question I’ve answered so excuse me.
When adding fractions, it’s easier to ask yourself how you can get the denominators to be the same. In this case, 1/4 can also be 2/8, if we multiply 1/4 by 2/2. 1x2 is 2 and 4x2 is 8. 1/4 and 2/8 are the same because 2/2 can also be written as 1, and 1 times anything gives the same answer.
Now we have 1/8 + 2/8, which would be 3/8.
I hope this answer helps! :)