Most of us work on a 90 minute block schedule already and plan three or four activities for each class.
Why not turn them into stations? Students can move at their own pace and you don't have to wait for the whole class to finish an activity before moving on to the next.
And its easy for you as the teacher to move between the groups to answer questions and offer suggestions.
English teacher, Caitlin Tucker, explains how the stations might work in the five minute clip below.