Exacty. A calculator is useless if you don’t know how to structure the problem and what and how to calculate it.

From the article: The long-simmering anger at soaring housing costs boiled over late last month, when 87-year-old Maricarmen Abascal, who uses a wheelchair, was evicted from the home she had lived in for 70 years. The octogenarian said she was unable to afford the 230% rent hike demanded by the investment fund that bought her apartment.