The most appropriate way to determine the mastery of Mrs. Blue's students in writing two-column geometric proofs would be to have them complete a formative assessment. A formative assessment is an ongoing evaluation process that helps teachers identify what students know and don't know, and provides feedback to help them improve their learning.
Mrs. Blue can use a variety of formative assessment strategies to determine her students' mastery of two-column geometric proofs. Some possible strategies include:
1. Exit tickets: At the end of each class, Mrs. Blue can ask her students to complete a short quiz or worksheet that assesses their understanding of the material covered that day. This will help her identify any areas of confusion or misunderstanding.
2. Peer review: Mrs. Blue can have her students work in pairs or small groups to review each other's two-column proofs. This will help them identify errors and learn from each other's mistakes.
3. Rubric assessment: Mrs. Blue can provide her students with a rubric that outlines the criteria for a well-written two-column proof. Students can use this rubric to self-assess their work and identify areas for improvement.
4. Mini-projects: Mrs. Blue can assign mini-projects that require students to create two-column proofs for a variety of geometric problems. This will give students the opportunity to practice their skills and receive feedback from their teacher.
By using formative assessment strategies, Mrs. Blue can monitor her students' progress, provide targeted feedback, and adjust her instruction as needed to ensure that all students master the skill of writing two-column geometric proofs.