Using writing assignments in high school geometry to improve students\u27 proof writing ability

The Common Core State Standards encourage the use of writing in mathematics classrooms. This study was designed to create a template for high school teachers to use in a geometry class to improve students’ proof writing ability. The students enrolled in the class were asked to complete journal and expository writing assignments throughout the course. The assignments were scored with a rubric. To assess if growth was made in proof writing, the students were all given a test four times throughout the school year. All four tests were assessed using the same rubric. We provide evidence that the template was successful in increasing the students’ ability to write geometric proofs by increasing their use of mathematical vocabulary, increasing their ability to use the information in a problem, and increasing their ability to justify their steps with correct mathematical facts or theorems