This custom NumWorks calculator case has been designed as a protective, functional, and educational accessory, intended for students, teachers, engineers, and professionals who use the NumWorks on a daily basis. Beyond providing full protection for the calculator, this case integrates practical tools directly useful in academic and technical environments, while preserving ergonomics, accessibility, and a clean design. The overall geometry has been carefully developed to remain compact, robust, and easy to manufacture using standard 3D printing processes.

One of the key features of this case is a perfectly flat side with integrated measurement graduations, allowing it to be used as a built-in ruler. These graduations are directly modeled into the design, requiring no additional parts, and are optimized to remain readable after printing with common layer heights and nozzle sizes. This feature enables quick and convenient length measurements for geometry exercises, technical drawings, electronics schematics, or general classroom use, especially in situations where carrying separate measuring tools is not practical.

The case also includes an integrated pencil / pen holder, positioned to avoid interference with screen visibility, button access, USB connectivity, and general handling of the calculator. This holder keeps a writing instrument securely attached to the calculator, ensuring it is always available when needed. The retention has been designed to accommodate most standard pencils and pens, providing a good balance between ease of insertion and secure holding during transport.

From a technical perspective, the model is optimized for reliable and accessible 3D printing, requiring no supports or only minimal supports depending on user preferences and printer capabilities. It is compatible with common filaments such as PLA, PETG, or ABS, and the wall thickness and structural reinforcements have been carefully chosen to provide effective impact resistance and long-term durability, while maintaining reasonable material usage and weight. Dimensional tolerances have been adjusted to ensure an easy fit, firm retention of the calculator, and safe removal without damage.

This design is intended for users who want to turn their NumWorks into a compact multifunction tool, combining a calculator, ruler, and writing instrument holder into a single object. It reflects a practical and educational design approach, aimed at improving organization, efficiency, and everyday usability, while showcasing the advantages of digital fabrication and thoughtful 3D-printed product design.