In this paper we report an analysis of a teaching sequence in which Grade 11 students were asked to produce some graphs corresponding to the relationship between time and distance of a cylinder moving up and down an inclined plane. The students were also asked to carry out the experience using a TI 83+ graphic calculator equipped with a sensor, and to discuss and explain the differences between their own graphs and the ones obtained with the calculator. We analyze the students' processes of meaning production in terms of the way diverse semiotic resources such as gestures, graphs, words and artifacts become interwoven during the mathematical activity. Our findings suggest that a complex relationship between gestures and words allow the students to make sense of the time-space graphic expressions. (Contains 4 figures.) [For complete proceedings, see ED500860.]