This paper investigates the methods used by teachers when teaching elementary mathematics to children with Swedish as their second language. The original mathematical terminology derives from Latin, Greek and Arabic, this terminology is not of great importance in this paper, the everyday language spoken in elementary classes when teaching mathematical concepts and calculations to younger children is. The use of everyday language is an advantage for children with Swedish as their second language as mathematical problems presented in a more plain language is easier to comprehend and solve than problems in mere numerals. Special teachers in home language classes often have the task of clarifying the mathematical concepts, introduced to the children during mathematical lessons, in the pupils first acquired language. A qualitative method was used in this study. The research material consists of interviews and observations. Two teachers and a home language teacher, all from one school, participate in the study. The research results show the importance of ordinary language terminology in mathematics for beginners. The participants of the study are aware of the importance of language in mathematics and actively work with the vocabulary in the languages involved. The various methodologies used to introduce mathematical vocabulary to the students differed among the teachers.