We suggest one that can be done in a group. Group work is a good way for students to interact with the instructor and each other. A class that interacts has less absenteeism . The student feels more connected to the class. We usually partition the class into groups of four.
Group work can be a homework problem session.
Our group work is often a data driven project or a computer lab project. Good problems can be found in the newspaper especially in the business section. Usually they are given a set of data with a series of questions to guide them in their modeling and problem solving. We often lecture the first part of the period and then allow the students to work in groups for the remaining time. It can take several classes to finish a project.