Have students do a written assignment on operations with polynomials.
Have a one question quiz at the start of each class. The first day the question is worth 20 marks. If they get it correct they are finished. Each day the mark goes down by one until everyone gets it correct. Make the question similar each time and go over each day's question before the next quiz. A question such as works well.
Provide a question similar to the one above and have them in partners simplify the expression. They must hand in one answer per pair and the first pair to hand in the correct answer gets a prize( a pail of suckers work well).