I think the correct question is
Charlie is eating five cakes but there were two missing cake at her grandma's house how many cakes did she have in total?
Answer:
The answer is 5 cakes
Step-by-step explanation:
Charlie is eating five cakes so we're certain he has five cakes.
If there were two missing cakes at her grandma's place, we can't with all certainty say that Charlie took those cakes from her grandma's place.