The National council of La Raza (NCLR), the nation's principal Hispanic constituency-based organization, seeks funding from the National Science Foundation's Informal Science Education Program for a four-year community-centered demonstration program. Project EXCEL-MAS, the Math and Science component of its EXCEL-MAS is designed to develop and encourage the adoption of supplemental math and science programs for at-risk Hispanic elementary and middle school students and their parents, using thematic, hands-on approaches; and ultimately help to increase the numbers of Hispanic student enrolling and succeeding in paths which lead to advanced study in math and science. Hispanics -- the youngest and fastest-growing major U.S. population, numbering 22.4 million or 9% of the U.S. population according to the 1990 Census -- continue to be most undereducated major U.S. population. Only about half of Hispanics are high school graduates, and fewer than one in ten have completed college; only about one-quarter of high school graduates have followed curricular tracks including the math, science and language arts needed for college attendance; national studies suggest that Hispanic 17-year-olds on average have math and science skills at the level of White 13-year- olds. Contributing to these problems are a lack of culturally appropriate, meaningful parent involvement or family-wide approaches to education, supplemental programs to motivate and support at-risk students, wrap-around social services for low- income students and their families, and efforts to promote more equitable Hispanic access to the full school curriculum.