Science: “Number sense in infancy is a building block for later mathematical ability,” say the authors of a study published this week in the Proceedings of the National Academy of Sciences. Ariel Starr of Duke University in Durham, NC, and colleagues studied 48 children at 6 months of age and then again at 3.5 years. To try to determine their intuitive number sense, the researchers showed the infants two sets of dots projected on a screen and looked for those children who noticed which set of dots changed in number. Three years later the children were invited back and given a series of standardized math tests. The children in the top 50% of the math achievement tests also had shown a higher intuitive number sense when they were infants. However, the researchers point out that math ability is incredibly complex and is also shaped by a number of other variables, including experience, education, and motivation. What they hope is that their research may eventually help educators to improve teaching methods.