Recommendation 1. Build on students’ informal understanding of sharing and proportionality to develop initial fraction concepts.Siegler, R., Carpenter, T., Fennell, F., Geary, D., Lewis, J., Okamoto, Y., Thompson, L., & Wray, J. (2010). Recommendation 1. Build on students’ informal understanding of sharing and proportionality to develop initial fraction concepts. In Developing effective fractions instruction for kindergarten through 8th grade: A practice guide (NCEE #2010-4039). Washington, DC: National Center for Education Evaluation and Regional Assistance, Institute of Education Sciences, U.S. Department of Education. Retrieved from whatworks.ed.gov/ publications/practiceguides. Public Domain