The Learning Units are not designed to be conducted as a part of classroom activities, nor intended to replace the textbook content. Interested students and teachers can identify suitable time slots within or outside their school hours for conducting these. Working through each Learning Unit will typically require multiple (about 2-4) sessions. Different Learning Units are designed to be conducted in different settings: some are best done sitting around a table or desk and some in a laboratory. Some may need a playground or an open area, while some may even need to go around a local marketplace. All units however are best done in groups with an appropriate time devoted to both conducting the tasks within and discussing the answers to questions given around the tasks. Many of the questions given have no single correct or unique answer. The discussion among the students on these questions is particularly important to gain fully from the Learning Units. The grouping of Learning Units as Class 8 and Class 9 is only indicative; these units could be done interchangeably and also with class 7 or class 10 students as the teacher deems fit.