Now the tools in my classroom match the teaching. Instead of using pencils and erasers to hide their mistakes, my students use pens to document the effort they put into their work. In math, I teach them that the changes they make show evidence of flexibility and persistence as they try different strategies to solve problems successfully. I teach my students that, in their writing, revisions document their commitment to the craft of writing. They learn that even inked corrections to simple errors like miscalculations and misspellings provide evidence of attention to accuracy and detail.