This study investigated the experience of preservice mathematics teachers working with example-eliciting tasks (EET) on an online formative assessment platform. The study focused on the effect of working with EETs on the preservice teachers' (PSTs) professional noticing of learners' mathematical thinking. Participants included nine PSTs studying for their master's degree in a teacher education college in Israel. The PSTs were presented with their own responses and peer's responses about an angle bisector activity, and semi-structured interviews were conducted following the completion of course meetings. Qualitative methods were used to analyse the data. The findings show that the PSTs' experiences of engagement with EETs were reflected in their noticing skills: attending, interpreting and responding. The findings also show that PSTs paid special attention to the variance between submitted examples and noticed the differences between answers. Their experiences also affected their knowledge of content and teaching, namely the proper sequence of instruction and the choice of examples for use in the classroom to facilitate deeper understanding of concepts. Finally, the findings indicate that using EETs on an online formative assessment platform enhanced the noticing skills of PSTs.