“The National Science Foundation, concerned with mathematics performance reported by National Assessment of Educational Progress and the consistently low performance on international assessments since 1970, made a decision to support the development of research based K-12 mathematics textbooks. The NSF realized that the vision put forth by the NCTM Standards might take many different forms, and ultimately funded 13 different projects that spanned K-12. These curricula were extensively field-tested in schools and then revised before becoming commercially available. The resulting mathematics curricula represent notable exceptions to traditional textbooks that typically lack a research and development phase prior to release The NSF-supported mathematics textbooks have been reviewed by committees of the US Department of Education and AAAS and judged of exemplary quality compared to other commercially available textbooks. Studies have consistently reported positive growth in the mathematics learning, particularly related to reasoning and problem solving, as a result of use of the new curriculum material” – Barbara J. Reys and Robert E. Reys, University of Missouri, NCSM Journal, 2007
TEKS curriculum material is supplemented with NSF sponsored curriculum material to enrich students mathematical skills in reasoning and problem solving.