As a basis for treatment of elementary school mathematical themas, a phenomenological scheme representing concepts as three component entities is given. Three related components: class of examples, mental image and name, serve very well as a piece of general language used in subject analysis. With regard to iconic representation of concepts, ``leaf'' used in that representation is considered as being a premodel of geometric plane. To underline that idea and hence, to avoid some often encountered discrepancies, the following rule which governs such representation is formulated: two icons occupying different places are different. At the end, the first topic ``Sets and Counting'' is sketched, setting forth the way how the meaning of words ``set'' and ``element'' can be assimilated at the initial stage.