The purpose of my study is to examine how four preschool teachers go about using the term play in children's early mathematical development. In order to fulfill the purpose of this study, I have the following questions:

1. How the preschool teachers visualize mathematics in children’s play?
2. What reflections have the preschool teachers about the importance of play for children's mathematical learning in preschool?
3. How do the preschool teachers see on their own role in the children's play?

In this study, I have conducted a semi-structured qualitative interviews based on the interviews with four preschool teachers from various departments in a preschool. I have also conducted some observations to complete my study. Whereas in my analysis of the researched material, I have used Vygotsky's theory.

The survey shows that the preschool teachers are aware of the use of mathematical language and concepts in children’s different activities which were conducted daily in the preschool. The preschool teachers are aware that the children learned and developed mathematical concepts by playing. They are also aware that materials are a resource that supports the children’s opportunities to learn mathematic. The preschool teacher’s role in children's play is to be present and observant, which means that they are receptive to children's needs during their playtime. It is also by being a cautious preschool teacher and by not interrupting the children's play, that the teachers be able to expand further the children’s play.

My research is relevant because it addresses the importance of play in children's early mathematical development. I have noticed that the preschool teachers have different opinions regarding their way at visualize mathematics in children’s play, their own role in the children's play and the importance of play for the children by learning mathematics.