The aim of the study is to find similarities and differences concerning the new formulations on teaching in revised curriculum in Swedish preschool and international research in early childhood education, Teaching is more clarified in the revised curriculum. Swedish preschool education is moving towards a more formalized approach where teaching is more visible (Helenius, 2018). There is a consensus that early mathematics is important in policy and research but there is no agreement on how mathematics education should be implemented. There are differences between and within countries, a clear difference is the relation between play and teaching (Palmér & Björklund, 2016). The concepts of classification and framing are used to discuss the visibility of pedagogics in the formalization of teaching mathematics in preschool (Bernstein, 2000). This is a literature review regarding research on teaching mathematics in early childhood education. It draws from a number of scholarly research article conducted between 2014 and 2019. The data collection is in progress. Qualitative and quantitative content analysis will compare emerged codes. The expected results will consist of empirical research. Ethical consideration is met by showing respect and responsiveness to other researchers work. This literature review is based on peer-reviewed articles. Preliminary findings indicate differences in how teaching mathematics in preschool is described. Preschool in Sweden has a tradition of a play-based pedagogy and no formal assessment of children as many other countries. Perhaps, the change may push teaching to become more visible and formal (Helenius, 2018). Implications for policy and practice will be discussed.