This project will serve the US national interest by strengthening undergraduate Earth science majors' proficiency and confidence with quantitative skills and reasoning, resulting in students who better understand Earth processes and are prepared for geoscience careers. It is a Tier 2 project on the Engaged Student Learning Track. Quantitatively skilled Earth science graduates are critical to meeting the needs of the workforce and the country. However, the application of math skills in a geoscience context is fraught with difficulties such as the uneven preparation of students, gatekeeper mathematics prerequisite courses, faculty who are not trained to teach quantitative skills, student math anxiety, and the cognitive difficulty of transferring mathematical skills to a specific science context. This project will develop the needed curricular resources and faculty professional development to significantly improve geoscience majors’ disciplinary math capabilities. <br/><br/>The project will improve the quantitative skills and confidence of Earth science undergraduates by a multi-pronged approach: 1) developing co-curricular modules to support majors-level quantitative skill development within Earth science courses and programs; 2) organizing faculty professional development for developing and integrating these resources; and 3) conducting educational research on effective implementation strategies and student skill progression and attitudes. Central to the resource design will be the application of math skills to Earth science applications with examples drawn from a variety of sub-disciplines. Module authors having a range of geoscience disciplinary expertise will be recruited to ensure broad applicability of the resulting resources. Assessment and evaluation will be carried out by the project principal investigators and an external evaluator. The modular approach will allow faculty to adopt modules appropriate for their individual courses and help scaffold quantitative skills across geoscience curricula or into dedicated quantitative geoscience courses. The free online module collection will be hosted on the Science Education Resource Center (SERC) site. The project will also work with SERC to improve instructor discovery of existing activity collections in which students can further apply the quantitative skills they have developed using modules written in this project. The NSF IUSE: EHR Program supports research and development projects to improve the effectiveness of STEM education for all students. Through the Engaged Student Learning track, the program supports the creation, exploration, and implementation of promising practices and tools.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.