Simple, introductory activities help assess prior knowledge on day and night. Such activities prepare the students for the lesson plans while giving them common background knowledge on the topic. A KWL chart works well for the topic. Make three different columns, one for what the kids already know, what they want to know and what they learned. The first two categories are filled out right away. The final column is completed after the day and night lesson. Another option is to read books that talk about day or night. A mix of nonfiction and fiction books for the second-grade reading level are ideal.
Lessons that compare activities during the day and night give the students a better understanding of the concept. A simple activity is to list several different activities. The kids categorize these into either day or night columns. For example, nocturnal animals sleeping goes under the daytime category. Another way to illustrate the differences is to have the students draw pictures of day and night activities.
A globe and a flashlight can be used for a simple experiment that illustrates what makes day and night. Dim the lights in the classroom. The flashlight represents the sun, which you shine toward the globe. The students are able to see that part of the Earth is in the light area from the flashlight's beam while the other areas are dark.
A journal writing gives the second-graders a chance to make their own observations about day and night. Have them document when they notice the sun going down over the course of a week or longer. Ask the students to write down what they see at various times of the day or night. To expand these activities, give the kids journal topics or questions to write about. Examples include what type of animals are active at night, how they feel at night versus during the day or what defines whether it is day or night.