Two questions about certainty in mathematics are asked. First, is mathematical knowledge known with certainty? Second, why is the belief in the certainty of mathematical knowledge so widespread and where does it come from? This question is little addressed in the literature. In explaining the reasons for these beliefs, both cultural-historical and…

The purpose of this study was to examine the reliability, validity, and predictive utility of 3 measures for screening kindergarten students for risk for math difficulty (MD). The screening measures assessed number sense and computational fluency, constructs central to typical early mathematical development. Conceptual and operational outcomes…

This article describes an activity through which students collect data and explore ways to display them through graphs and charts. It also motivates various summary measures for location, spread and shape. Finally, it gives an introduction to concepts of validity, reliability and unbiasedness.