This paper uses multimodal discourse analysis to show that discursive form, in addition to words, gestures and sound dimensions of speech, is an important linguistic resource for expressing mathematical meaning. During a collaborative task, a student spoke an insight about an algebraic property five times over a few minutes, in slightly different ways. He consistently used repetition of grammar and words, a speech form known as poetic structure. These poetic structures were marked elaborately through discursive modes such as pause, intonation and gestures, suggesting that they form a meaning-making mode that is real to the speaker. [For complete proceedings, see ED581294.]