Researchers point at the need to study the creative processes of students in problem solving, as these may indicate how to encourage creative problem solving. The present research attempts to study, based on the heuristic framework of Polya, pre-service teachers' flexibility processes when they solve a mathematical problem with technology. The research was held in a teacher college, where two second-year classes of 49 mathematics pre-service teachers (24 in the academic year 2017-2018 and 25 in the academic year 2018-2019) participated in the research. The pre-service teachers were requested to solve the halving-the-rectangle problem with technology, specifically with the GeoGebra software. The research results indicated that generally the participants, who performed flexibility processes, used a sequence of creativity processes: conjecturing, specialization, verifying consequences with technology and generalization. The conjecturing process utilized mathematical relationship or inference from analogy, where the inference from analogy advanced gradually through solution modifications.