• While circulating around the room, observe whether students are engaged in large-group and paired discussions. Make note of student responses throughout your observation.
• Monitor students’ ability to explain the patterns on a calendar such as day and night, phases of the Moon, and seasonal occurrences. Make note of students’ interactions throughout your observations.
• Individually assess each student’s knowledge of day and night through informal discussions.
• Assess students’ understanding of natural and human-made systems as they classify various systems on activity sheets.

Activity 1: Introduction to Systems

Begin this lesson by writing the word system on the board. Ask students what they think system means, or give an example of the word. Students may or may not know the definition, but may say “like the solar system.” If students are having difficulty giving examples of systems, begin saying and writing examples such as:

Solar system                Human body system(s)

An aquarium               School system

Ecosystem                   Bicycle

The ocean                    The rainforest

Tell students these are examples of systems. Scientists classify a system as either a human-made system or a natural system. Have students look at the list again and discuss what the difference might be between a natural system and a human-made system. After discussing various systems and their characteristics, give students the Classifying Systems sheet (S-3-5-3_Classifying Systems.docx).

Activity 2: Taking a Look at Two Systems

Engage students by inviting them to your meeting area to see a picture of the solar system and a calendar. Ask students to identify these two types of systems. Students should respond that the solar system is a natural system and the calendar is a human-made system. Ask: “Why is the calendar a human-made system? Why do we have calendars? Is there a connection between the calendar and the solar system? How do these two systems depend upon each other?” These questions may be placed on a chart and reviewed at the end of the lesson.

Give each student or student pair a calendar. Note: It would be more effective if each student or pair had a different calendar. Allow students time to look at their calendar and then ask, “Do you see a pattern in your calendar? Does your calendar indicate when the seasons change? Do you see any other patterns on your calendar? Who developed our calendars? Are all calendars the same? How does a Leap Year affect our calendar? ” Discuss student responses.

Write the words Moon, Earth, Sun on the board. Tell students, “These are the parts of the solar system that we are going to be investigating. The Sun, Moon, and Earth are part of a natural system. Before the development of the calendar, humans used the solar system to help them keep track of time. How would the solar system be useful in keeping track of time? Is it the best way to keep track of time? Why or why not?”

Gather students and read What Makes Day and Night (Let’s-Read-And-Find-Out Science) by Franklyn M. Branley. Discuss the book with students and review the questions that were asked at the beginning of the activity. Again, ask students to tell what a system is. Give examples of at least two types of systems.

Have students write in their science notebooks the information they thought was most important in the lesson and why.

Extension:

• Students who might be going beyond the standards can research different calendars used throughout the world.

• Students who may need more practice can select a special day on the calendar and tell why it was important to add information about it to the calendar. Allow students the opportunity to share with the class and display their work in the classroom or the hall.