To support students' development of concepts in mathematics, the use of technology is often encouraged (Common Core State Standards Initiative [CCSSI] 2010). Technology can contextualize learning and provide a meaningful setting for mathematical ideas. Most teachers are supportive regarding the use of technology to encourage learning and understanding in mathematics. However, using technology can present many challenges. Particularly, technology training is not as strong as it could be in supporting teachers' growth and ability to create lessons, and most teachers would like support in using technology in the classroom. To address this concern, this article presents a guide for an activity using graphing calculators and Calculator-Based Ranger™ 2 (CBR) as the technology to support understanding of position/time graphs with preservice elementary school teachers. This activity supports a grade 6 standard from the Common Core State Standards for Mathematics (CCSSM) that encourages students to see the relationship between variables in real-world situations. Students should "analyze the relationship between the dependent and independent variables using graphs and tables". This activity allows students to experience how their distance from the CBR (dependent variable) changes the graph as related to time (independent variable). CBRs are sonic motion detectors designed to be used with graphing calculators (specifically the TI-83 Plus and the TI-84) and can collect data on motion, including distance, velocity, and acceleration. Additionally, one of the preservice teachers taught the same lesson individually to a fifth-grade student who sometimes struggles in mathematics. The teacher's reflections are included. A bibliography is included.