Final answer:
Creating a budget by listing every material, resource, and contract worker for a project refers to the bottom-up approach, which helps in establishing a detailed and accurate budget.
Step-by-step explanation:
When a project manager is creating a budget by thinking about every material, resource, and contract worker that will be required from the beginning to the end of a project, this is known as a bottom-up approach to budgeting. This method involves starting at the most fundamental level, determining the cost of each detailed part of the work and aggregating them to come up with the total project cost. The bottom-up approach ensures that no aspect of the project is overlooked, leading to a more accurate and reliable budget.