References
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Smith,M.S. & Stein, M.K. (1998). Selecting and creating mathematical tasks. Mathematics Teaching in the Middle School,3, 344-350.
Stein, M.K. & Smith, M.S. (1998). Mathematical tasks as a framework for reflection: From Mathematics Teaching in the Middle School, 3, 268-275.
Van De Walle , J., Karp, K., & Bay-Williams, J. (2012). Elementary and middle school mathematics: Teaching developmentally . (8th ed., pp. 36-37). Pearson
Smith,M.S. & Stein, M.K. (1998). Selecting and creating mathematical tasks. Mathematics Teaching in the Middle School,3, 344-350.
Stein, M.K. & Smith, M.S. (1998). Mathematical tasks as a framework for reflection: From Mathematics Teaching in the Middle School, 3, 268-275.
Van De Walle , J., Karp, K., & Bay-Williams, J. (2012). Elementary and middle school mathematics: Teaching developmentally . (8th ed., pp. 36-37). Pearson