Across multiple age groups and academic disciplines, research has shown that incorporating multimodal signs into instruction can enhance student learning. For instance, gesture might be synchronized with speech or written signs. The present study reports on the semiotic resources used by a teacher-researcher to support kindergarten students' developing understanding of the equal sign. An analysis of seven classroom lessons designed to advance students' understanding of the equal sign and equations in various forms revealed four categories of language and two categories of gesture used by the teacher-researcher that were specifically related to mathematical equivalence. Our findings contribute to understanding the role of multimodal signs in supporting instruction on mathematical equivalence. [This is the online first version of an article published in "Mathematics Education Research Journal."]