Children's involvement in home literacy and numeracy activities has been linked to school achievement, but the subtleties in the home environment responsible for these gains have yet to be thoroughly investigated. The purpose of this study was to determine how children's interests and collaborative parent-child interactions affect exposure to home literacy and numeracy activities. Parents of 170 four-to-five year old children completed a survey about their child's home learning environment. They rated their children's interests in 14 activities, and the extent of parent-child collaboration on a cooking and card-making task. Follow up interviews were also initiated with four mothers to provide validation of the survey data in numeracy. Factor analyses reduced the number of survey items. Parents whose children preferred exploratory, active or crafts activities reported frequent engagement in literacy and numeracy activities. Parents seeking a collaborative approach during activities reported increased exposure to home literacy and numeracy activities than families with less collaborative involvement. Interview data confirmed that parents of children with high numeracy scores were exposing their children to rich numeracy activities during play. The findings suggest that children's interests and collaborative parent-child involvement impact literacy and numeracy exposure in the home.