Mathematics takes place in a major part of human life and mathematical concepts are used in every part of daily life, starting from the age of infancy. The present study concentrates on the age of 11 months to two years, during nursery education, when formal, informal and non-formal activities enable infants to have experiences related to mathematical concepts. Nursery teachers are expected to include play-based activities at every stage of the teaching process, while parents are recognized as young children’s first educators. We examined nursery teachers’ and parents’ beliefs and practices about the development of the infants’ mathematical skills through the use of play-based activities and their respective roles. The present study was conducted in Cyprus, where obligatory preschool education is only one year before primary education. Questionnaires, interviews and shared diaries with home activities were used for quantitative and qualitative data. Results indicated that both groups of participants expressed positive conceptions on the value of daily life play-based activities which could support mathematical learning. However, it seemed that in the case of parents there was a lack of relevant knowledge about the use of attractive and creative activities which could relate to plenty of mathematical concepts. Parents recognize the vital role of teachers and they asked for further guidance and support. We discuss how we can ensure the quality of early mathematics informal teaching and nonformal learning experiences can be offered for all infants. We discuss the role of the Curriculum in Mathematics at nursery school under a play-based context and the guided parental involvement.