As needed, revisit any work with differential equations that may be outstanding from yesterday’s lesson. This might include the free response question from 2008 #5, or extra practice solving differential equations if students had a lot of questions on the differential equations problems from last night’s homework. We will continue reviewing differential equations over the next few days before students’ test, so another option is to postpone this extra practice if you are running short on time or want to spend more time in the Investigation section of today’s lesson.