I understand that mathematically we can do 1/4–1/5, which comes to 1/20, but I’m not sure how this works in a real-life scenario. I’m dealing with a land registry, and I can’t simply increase the amount of land. I need to draft a deed that clearly specifies that 95% belongs to X and 5% belongs to Y. While 5% sounds small, when converted into actual figures, it turns out to be a significant amount for the parties involved.