Science at key stages 1 and 2    (Year 3)

• Let children explore shadow formation using torches and other light sources eg OHP and objects of different shapes and different materials. Introduce children to the idea of light travelling from a source by shining a powerful torch beam through a comb with widely spaced teeth or a cardboard tube and showing that the beam is blocked and doesn't bend round corners. Show that a shadow is formed on a screen. Ask children to record what they see in drawings and writing.

• On a bright sunny day visit the school grounds to observe shadows, possibly including those formed by clouds. Suggest children explore shadows of themselves in different positions eg standing, crouched down, with arms extended. Record some shadows (not of clouds) with chalk on the tarmac. Later in the day look to see if the shadows are in the same place and are the same size and shape. Talk about the shadows with the children and ask them to make drawings to show their observations and to describe what those show. Encourage children to try to explain how the shadows were formed.

• At different times during a bright sunny day visit the playground and set up a stick. Ask children to measure and record the length of the shadow at different times of day. Ask children to predict eg by drawing on the ground the height of the shadow at intermediate times. Help children to present their results in a table and to make a bar chart showing the length of the shadow at different times of day.

• Remind children of earlier work and ask them to think about where (or whether) the Sun shines into the classroom or room at home in the same place all through the day. Ask children whether it follows the same pattern every day and suggest they observe it every sunny day over a period of two weeks. Ask them to think of a way of recording their observations eg by putting stickers on the window at the same time each day or by making sure an object is always in sunlight. At the end of the period question children about observations and whether the Sun appears to move in a regular way.

• Take the children out in the playground on a sunny day and ask them to mark the direction their shadow is pointing in and the direction of the Sun. Remind them of the dangers of looking at the Sun. Ask children to explain what these marks show. Set up a shadow stick in the playground and mark south, east and west in relation to it. At regular times eg 9.00, 12.00, 15.00 over a period of several days mark the direction and length of the shadow and the direction of the Sun.

• Use a model eg a powerful torch and a short shadow stick to illustrate that the higher the light source is the shorter the shadow, and how changing the relative position of the torch and stick causes the length and position of the shadow to change. Talk with children about whether they think the Sun does in fact move. Illustrate using models eg a model person stuck on a globe or secondary sources that the shadows can change as we move and the Sun stays still.

• Use secondary sources eg reference books, CD-ROMs to investigate how sundials were used and constructed. Make a poster illustrating how they worked and some of their limitations.

• Remind children of earlier work when they saw shadows of wide-toothed combs and possibly demonstrate this again. Present children with a collection of objects/material including some that are opaque, some that are transparent eg plastic bottles, colourless and coloured acetate sheets and some that are translucent eg fine net, thin nylon, greaseproof paper. Ask children to make a prediction about what will happen when a strong torch is shone on to them. Ask children to test their predictions, to record their results and to compare them with the predictions made. Help children to write an account of what they did and what they found out.