A Study of Math Curricula in the United States
http://www.mathematica-mpr.com/Newsroom/Releases/2010/MathStudyYr2_11_10.asp and the formal report which include the data and analysis can be read in http://www.mathematica-mpr.com/publications/PDFs/education/mathcurricula_fstsndgrade.pdf.
Key aspects of this curriculum include application of accessible algorithms that can be more easily understood and used by students; use of student math drawings and research-based visual representations to support student understanding and class discussion of mathematical thinking; an emphasis on in-depth sustained learning of core grade-level concepts (rather than a spiral curriculum) to support students’ conceptual understanding and fluency; and a “learn by teaching” design to support teachers new to the curriculum.Contrast the above study with DepEd's Secretary Luistro's view:
"Mapapagbuti na natin ang kaalaman ng mga mag-aaral sa Agham at Matematika sa pagsusulong ng spiral approach sa ating bagong curriculum," the DepEd chief said. (With the spiral approach in the new curriculum, we will improve learning in math and science)