Ones of the greatest difficulties in teaching and learning the limit concept lies not only in its richness and complexity, but also in the extent to which the cognitive aspects cannot be generated purely from the mathematical definition. In this paper, the author designed basic mathematical tasks which will guide students who are learning of the limit of sequence. It has been shown that experiments that use dynamic manipulation enable students to more easily forming hypotheses, verifying them, rejecting wrong hypotheses and come to a full understanding of limit of sequence.