Complex sentence: Her first jobs included being a computer operator for an ambulance service, and secretarial work for a large corporation in Culver City, adding up to 16 hours a day for 5 days a week.
Split into simpler sentences: Her first jobs included being a computer operator for an ambulance service, and as a secretary for a large corporation in Culver City. This added up to 16 hours a day for 5 days a week.