Which strategy would best serve Mrs. Hamm's goal of improving her students' understanding of comma usage?

A mini-lesson is particularly effective for Mrs. Hamm’s goal of improving her students' understanding of comma usage because it allows for focused, direct instruction on a specific topic. In a mini-lesson, the teacher can clearly explain the rules and functions of commas, provide examples, and demonstrate how commas are used in various contexts. This structured approach is helpful for students to grasp the foundational concepts of comma usage in a short and concise format.

By incorporating visual aids, examples from students’ writing, and opportunities for guided practice, a mini-lesson can effectively engage students and foster a better understanding of the subject matter. Additionally, it sets the stage for further activities, such as peer editing or rewriting, where students can apply what they've learned in a practical context.