What makes a shadow?

Learning intention

• Establish prior learning.

Set up a learning centre. Collect pictures of shadows, books from the school library and Te Puna Mātauranga o Aotearoa National Library of New Zealand, photos, and magazines of different types of shadows. Display a vocabulary chart and add to this throughout the unit, e.g., shadow, shine, sun, cloud, sky, creating, behind, in front, positions.

Engage students in a class discussion.

• What do you know about the sun and shadows? Student ideas may include: it’s dangerous to look at the sun; the sun creates shadows; without the sun we would not have shadows; or the moon can make shadows. Look for shadows in the classroom.
• What makes the shadow?
• Does the shadow look like the object? How is it different? Record on a KWL chart.
• Ask students what they want to find out about shadows. List three or four questions about shadows in the "What we want to know" section of the KWL chart.

Tracing a shadow

Ask for a student volunteer. Turn on a strong source of light, such as a lamp, and turn off all classroom lights. Students observe the student's shadow being cast in the classroom. Ask the students where the light source is and where the shadow is cast. Explain that the sun is similar to the light.

Demonstrate how to trace the shadow by following the outline of the student's shadow with your finger.

Choose a student to pick an object from a bag and place it in front of the light source without the class seeing the object. Have them guess what the object is. Discuss the shadow that the object makes. Show the class the object. After all the objects have been used, choose a student to select one of the objects and put it back in front of the light. One student can trace the shadow on a piece of paper on the board. Students compare the object to its shadow. Discuss the size and shape of the object and the shadow.

Shadows in texts

Read What Makes a Shadow by Clyde Robert Bulla and discuss the shadows that were made in the story. You can find read aloud videos of this story online.

1. Students make shadows on the wall with a partner. Students use flashlights and objects to make the shadow. Have them trace some of their shadows on paper.
2. Hold up a hand and ask students what kind of shadow they think it will make. Discuss other shadows that could be made using a hand. Make shadows of animals using hands. Choose students to make different shadows and have the class guess what the shadow is.
3. Share the story of Peter Pan and his Shadow. Teacher and students discuss shadows and how they are different from the real object. Students use their imagination to suggest things that could happen to the shadows.

Learning intention

• Explore and make shadows.

Activity 1

Explain that each student will use chalk to trace the outline of their partner's shadow on the playground.

Remind students to never look directly at the sun but to concentrate on the shadows.

Have the students in pairs find a place in the sun and make shadows by standing, running, making body shapes, and so on.

Begin by outlining the partner's shoes or feet. This is important as the students are going to trace shadows at different times throughout the day.

Make sure that every student gets the opportunity to create a shadow.

Activity 2

When the students have completed the outside tracing, have them draw their partner, their partner's shadow, and the location of the sun.

Model writing a caption for the shadow tracing: Have the students write a caption for their drawing.

NB: Throughout the unit, take photos of the students and shadows to use later for discussion and motivation for writing. Make into a book or a wall story, Our Book of Shadows.

Activity 3

Two or three hours later (or the next day), after students have completed their first shadow tracings, have the students go outside again to observe their shadows and make a tracing of what they now see.

• Ask students to predict if their second shadow tracings will be the same or different from the first shadows they drew. Record their predictions.
• Return to the playground. Have the students reposition themselves in their original places, using their feet or shoe outlines as a guide.

Discuss with the students what they observed:

• Did anything change?
• What looked different?
• How many shadows changed?

Revisit previous predictions. Discuss how many students predicted correctly. 

• What do you think made the shadows?
• How can you explain that?
• Did the sun move?
• Did we move? (Explain to students that shadows move as a result of the Earth's motion.)

Teacher and students: What else have we learned and need to add to the KWL chart? Have we answered our first questions? Have we any new questions? 

Have students discuss the information they have discovered about their shadows' lengths and other observations on shadows made by the sun at various times during the day. Teacher and students work together to complete a table for this information and then write some concluding sentences. Read and display these in the class.

Activity 4

In the classroom, have students observe the sun shining through the windows and look to see where shadows are being made. Ask the students to explain to each other, in pairs, why they think shadows happen.

View this activity on Scootle – Light and shadows. Allow students to play with the interactive part of the activity, investigating how shadows change based on the position of the sun.

Using different objects, encourage students to create, trace, and manipulate shadows.

Encourage students to question:

• How can you "make" a shadow?
• What is the light source?
• How is the shadow similar to the object you used to make it? How is it different?
• How can you change the size of your shadow?
• How can you change the shape of your shadow?

Learning intention

• Process information and express knowledge about shadows.

Read to the students Shadow Bear by Frank Asch - a delightful story of a little bear who attempts to escape a shadow that seems to be chasing him.

Following the reading, discuss:

• What do you know about shadows that makes this book funny?
• Why did Bear's shadow disappear when he hid behind a tree?
• Why did the shadow disappear when he buried it?
• What makes a sun shadow fall one direction at one time and another direction earlier or later in the day?
• What other questions do you have about shadows?
• What time of day do you think these events happened, and where was Bear's shadow at these times?

Reread Shadow Bear. Identify those aspects of the story that are purely fictional and those that "could happen", paying particular attention to how shadows change during the day.

Add to KWL chart - have we found answers to our questions? What else have we found out about shadows? Do we have more questions?

Work together to complete the Questionnaire - What makes a shadow? found in Materials that come with this resource.

Shared reading

Read a selection of appropriate texts and/or Junior Journals exploring the language and text features of explanations. Explain to the students that they will be writing an explanation about shadows.

Use models of explanation writing from exemplars to read and discuss with students. Read the explanation with the students. Talk about the explanation: How do we know this is an explanation? What impact does the explanation have on us as the readers? How would the author have gathered this information? List student responses on a chart.

• Discuss and identify which explanations are about the "why" and which are about the "how". Talk about what it is in a sentence that tells us about these differences.
• Identify action verbs and discuss their functions in organising explanations. Action verbs can be identified and discussed in terms of their function as part of a sequence of processes that explain how things happen or work, or which explains why one action causes another action.
• Discuss the use of conjunctions to link groups of processes, eg., first, next, then, when, because, so that, therefore.

Continue to read closely a selection of explanations. Discuss explanations extensively before asking the students to write an explanation. Encourage students to include a reason and use words like "because" or "then" to join their ideas when talking about an explanation.

Discuss with the students:

• What have we found out about shadows?
• What is a shadow?
• What makes a shadow? How?
• What do we have to remember when we write an explanation?

Model how to brainstorm and then how to organise ideas into sequential order, thinking carefully about how to start and end the explanation. Model how to select the best and most relevant ideas. Ask students for ideas, encouraging them to participate in the modelling process. Talk about the audience for their writing. Who will read it?

Model writing an explanation: How is a shadow made?

Model how to complete the Checklist - What makes a shadow? found in Materials that come with this resource. Encourage students to identify the checklist points using the teacher modelled writing.

Student writing – explanations 

Students work in groups to show and explain the different shadows they have made. Encourage students to talk about what they have found out about shadows. Reread the modelled writing. Students brainstorm and draft their own explanation of "How is a shadow made?" and illustrate it with a sketch of someone/something and its shadow.

Conference with the teacher. Edit and proofread.

Students complete the Checklist - What makes a shadow? found in Materials that come with this resource. Some students may need teacher assistance.

Self-assessment

Teacher models the Self-assessment - What makes a shadow? found in Materials that come with this resource. Each student completes the self-assessment. Some students may need teacher assistance.