A very successful strategy to involve students from different classes is a lessons that focus on a piece of current events that is presented in all levels of competence. The common trait is that the cultural topic is presented to all classes, but each group of students will work on activities with an increasing level of difficulty.
One of the positive aspects of vertical units is that when students realize that they share the topic with other classes -especially of higher level-, usually they feel motivated and intrigued to find out more about the lesson. The activities are then proposed to students with different levels of difficulty. The examples proposed are on: