According to Hunt's match hypothesis, the accuracy of parents' beliefs about their children's abilities can influence the nature of the early learning experiences they provide. The present study examined the accuracy of parents' beliefs about their preschoolers' number development and relations to parent‐reported frequency of engaging children in number related experiences at home. Parents reported engaging their preschoolers more frequently in conventional numeracy activities, (i.e. counting and identifying numbers) than advanced number‐related activities (e.g. arithmetic) at home, though the frequency of advanced activities increased with the development of children's advanced number skills. Parents were most uncertain about their children's advanced number skills, though they demonstrated an overall tendency to overestimate their children's abilities across number tasks. Increased rates of overestimation and decreased rates of underestimation were associated with increased incidences of advanced activity engagement at home. Thus, results suggest guiding parents to understand their own children's numerical understanding in a wide range of number domains could promote more advanced at‐home number‐related activity engagement. Copyright © 2016 John Wiley & Sons, Ltd.