The aim of this paper is to investigate the role that auxiliary means (manipulatives such as cubes and representations such as number line) play for kindergartners in working out mathematical tasks. Our assumption was that manipulatives such as cubes would be used by kindergartners easily and successfully whereas the number line would be used by kindergartners rarely and usually unsuccessfully. Through analysis of the 20 children's (5-years-old) answers which concerned the number sequence as well as simple addition and subtraction problems it appears that although the children mostly used cubes they did not always use them systematically or successfully. The effective use of the number line was limited to defining the number sequence. (Contains 4 tables.)