In this case, we want to write an expression representing the number of hours worked by Sarah. The key phrase in the sentence is ... more ... than ... This indicates that we should add two things.
... + ...
The two terms that we are adding together are 8 and the hours worked by Paida. Let p represent the number of hours worked by Paida. Even though 8 comes first in the sentence, it can be on the right-hand side of the addition.
p + 8
Note that this is only one of the multiple ways to algebraically express the given verbal expression.
