National Mathematics Advisory Panel, 2008). However, Ginsburg and Ertle (2008) provide several key reasons that professional development should target teachers’ mathematics knowledge. First, teachers need to understand the mathematics that children are learning and how they may be thinking. According to Ginsburg and Ertle (2008), “to understand … students’ mathematical thinking and then build on it in a way that encourages continued enjoyment of the subject, the teacher must therefore understand the mathematics that the thinking involves” (p. 55).
Second, teachers will be more effective implementers of mathematics curricula, as recommended by NCTM and NAEYC, if they understand the mathematics well themselves. At the pre-service level in particular, this means that teachers may need coursework related to deeply understanding the important mathematical concepts of early childhood rather than simply general mathematics courses that might be appropriate for college students, such as calculus.
Third, teachers can take advantage of teachable moments in mathematics only if they carefully observe, accurately interpret, plan, and implement appropriate activities to further learning, all of which require deep mathematics knowledge. Given that, until recently, teachers may not have had to teach mathematics in early childhood settings, that few have received professional development in early childhood mathematics education, and that many early childhood educators have limited professional preparation in general, researchers and professional organizations have recommended that professional development address teachers’ knowledge of mathematics (National Association for the Education of Young Children and National Council of Teachers of Mathematics, 2002).
Mathematics beliefs. As noted earlier, teachers have quite strong beliefs about mathematics, with many feeling it lacks key significance in early childhood programs. Ginsburg and colleagues (2006a), in describing efforts to provide training to teachers using the curriculum, Big Math for Little Kids, stress the importance of directly addressing the emotionally charged beliefs that teachers may have around mathematics. In fact, many early childhood teachers report they are uncomfortable with mathematics (Copley, 1999) and identify it as their weakest subject (Schram et al., 1988). In the prekindergarten settings in which the Ginsburg et al. (2006b) study took place, there appeared to be more resistance to mathematics than is typically found in kindergarten and elementary school, in which mathematics has long been expected to be taught.
Children’s mathematical development and curriculum. Naturally, professional development in early childhood mathematics includes helping teachers learn about children’s developmental progression in various areas of mathematics, the specific learning experiences they can plan, and the