Developed an interactive Bash script for the dianaelena1/OS repository that enables users to input numbers and calculates their sum until a zero is entered, providing a clear header and formatted output. The implementation emphasized maintainability by including comprehensive code comments and a dedicated testing scaffold, supporting future validation and extensibility. Work was tracked through three incremental commits, each documenting progress and improvements. Utilizing Bash and shell scripting skills, the developer focused on user-facing scripting capabilities and laid the groundwork for repeatable testing. No bug fixes were recorded during this period, with efforts concentrated on delivering this new feature and its supporting infrastructure.