When students make careless mistakes on their math papers, sometimes I ask them to rework the problem. Many times they don’t erase well enough for me to decipher the new answer or they complain about having to erase. I use dot stickers (found in office supply stores or local chains like Wal-Mart or Target) to cover up the wrong answers. When the papers are handed back, the students automatically see which problems need to be redone. This also serves as a quick visual indicator to help parents identify possible problem areas for their child.