 In this study, she gave three- to five-year-old children a task that did not require symbol use or arithmetic calculation, while also testing their math ability and vocabulary size.Feigenson found a correlation between children's approximate number sense and their mathematical ability even after controlling for children's vocabulary size and math ability before they received formal math education.In another study, Feigenson examined the limits of infants' quantification of small object arrays, using a four-object array to examine how infants represent information.