A designated amount of time is usually planned for each lesson. The schedules of other teachers and the need to give sufficient emphasis to all areas of the curriculum dictate the need to identify specific amounts of time to be used. Often there is room for flexibility but a teacher needs to avoid continuous overemphasis on a few favorite areas which may result in leaving out very important, difficult, or disliked subjects. Identifying 9:00 to 9:45 for a lesson shows respect for the need of a balanced curriculum which provides for the total child. Some school systems recommend a specific amount of time for each subject area; others do not. State guidelines usually indicate what should be taught but not how much time should be spent on an area.

Sometimes a total day may be set aside for a field trip or project related to a particular area. This is appropriate. Often teachers note ways in which other subject areas can be taught in such practical settings.