As students finish they must compare their work with others who have finished.
NOTE: If there are any who are especially slow to finish, encourage them to work together to finish. Encourage hesitant students to take their “best shot” by explaining that making a mistake here is actually a useful thing to do!
Students are to find someone who has an answer different from their own. They are then to work with that person until the two agree on an answer. Then, as a pair, they should seek out another pair or person with a different answer and repeat the process. Then as a group they will search for another person or group with a different answer until the entire class is either in agreement or deadlocked.
NOTE: Instruct individual students finishing later than others that they may join in any group that has an answer different from their own if they cannot find a single student to partner with.
Have volunteer(s) with different answers (hopefully all will arrive at the same answer and there will be only one problem posted) put the problem on the board and explain the steps. Correct any misunderstandings and repeat with problems from your text until students develop confidence.
Assessment of this activity depends upon whether the instructor wishes to assign a grade or merely monitor the process. Assessment of the activity can be by:
Observation—Circulate among students, listening to arguments and correcting (but only when absolutely necessary). Monitor carefully to be sure that weaker students are fully participating. Errors that seem pervasive may warrant a full class discussion
Writing—Give students an example problem, have them work it completely and explain each step in their own words. (If many students are having difficulty or if this was an introductory activity, you may supply the correct steps and have them do only the explanation.) The final work can be placed in a portfolio or a journal.
Calculation—Vary numbers in one or more of the problems worked by the class and have students turn those in to you for grading.