<p>This study addresses a crucial need to deeply understand the nature of creative engagements in mathematics education involving dynamic interactions with materials, tools, and diagrams, often within the context of uncertainty. There is little research on how this process can lead to unexpected insights, highlighting the agency of non-human elements. Recognizing the active role of these materials and diagrams and the dynamic nature of creative engagements, this study draws upon the theoretical concepts of new materialism and plural speech to explore this issue. This study focused on a student’s folding process evolving through the interaction with materials, tools, and diagrams as an assemblage of different materialities. The student participant, the focus of the current study, was a seventh-grade student enrolled in a public school who participated in a program on mathematics and visual arts. The data collection tools were the student’s diagrams, foldable cardboard models, and video recordings. The analysis was carried out through the lens of plural speech in order to depict the conversation between different materialities. After a fine-grained microanalysis of the student’s talks, hand gestures, diagrams, manipulation of cardboard material, and use of measurement tools, the findings of the study showed that the student experienced various contradictions, which resulted in reconfigurations of diagrams and folded materials. Ongoing conversation within the assemblage of different materialities resulted in the discovery of a method for creating an irregular triangular pyramid. It is anticipated that the findings will shed light on further studies on mathematics and arts from a new materialist perspective.</p>