Take the students for a walk outdoors on a sunny day to have them observe shadows. Warn students about looking directly at the sun, but have them follow the line of light as it falls. Objects break that light, resulting in shadows. As they walk, have students observe their shadows getting larger, smaller and disappearing all together. Provide student-size sheets of butcher paper. On a concrete surface in sunlight, have students trace each other’s shadows. Let them color and hang up their shadow outlines. Show how all light creates shadows using a lamp inside the classroom on a variety of smaller objects chosen by the students.
Have students choose an object to observe outdoors, such as a flower, bush, bench or bicycle. Take pictures of the object's shadow. Check the shadow in the morning, after lunch and later in the afternoon, and measure the shadow's length and position to show students that shadows change with the position of the sun. Have them draw pictures of their shadow experiment. Give each student a flashlight and have them use it to move closer and further away from an object and at different angles to better understand how shadows are formed and why they change shape.
Put a lamp in front of plain screen. Show students how they can use their hands to make shadows on the screen. Make a fluttering butterfly by crossing your open hands and interlocking your thumbs. Moving your hands and arms creates the illusion of the butterfly moving. See what other shadows the children can make. Let them work in pairs to think of ways to create shadows of animals or objects the other children will recognize.
Have students cut out large circles of cardboard to make sundials. Have them stick a straw or pencil up in the middle of the circle and mark their circles in half, quarters and eighths. Place the circles in a location where they’ll receive full sun. Several times during the day, have them check and mark the time and position where the shadow hits on the sundial. Explain how sundials were used to tell time before the invention of the clock. Download a picture of a sundial for the first grade students to color.