Argumentation is an important mathematical practice, highlighted by research and policy documents that describe ways to structure reform-oriented classrooms (Nardi and Knuth 2017; NCTM 2000; NGA Center and CCSSI 2010). Participating in argumentation can enhance students' mathematics learning as they make sense of mathematical ideas, provide evidence for claims, and work to convince others. To accomplish this, students need to know both something about arguments in general (e.g., that they should provide evidence in support of a claim) and something about the content for which they are arguing (e.g., how to select mathematically convincing evidence for a given content area). The authors adopt the language used in science education, where :"domain-general knowledge" refers to the knowledge of processes and practices in mathematics that students use across multiple topics, and "domain-specific knowledge" refers to the specific mathematical content students use in order to employ a practice such as argumentation (McNeill and Krajcik 2009). Teachers can support students to develop both types of knowledge as they begin to produce their own arguments, orally or in writing. In this article, the authors suggest ways to include transparency to questions and prompts during oral argument-- questions and prompts that support domain-specific knowledge--to include a rationale for the questions in prompts. When teachers are transparent about the process of producing an argument, it can support students as they work to produce written arguments of their own.