This set of 30 "I have, Who Has" cards is a fun way to get students speaking out loud in a math classroom. Students will read their cards and have to listen for the two points that describe the slope of the line on their card. I usually have students work on a separate piece of paper and give them a minute to work before letting someone say out loud that it is their slope and continuing on.
My students love being able to talk in math class, rather than just doing problems. You can also use this as a group activity and have all students write down and do the work for each question to what is being read, instead of just listening for their own card.