2. Exploring the properties of air
In the Key Activity of Module 1 Section 4 , pupils observed and researched things that move in air. Activity 2 integrates well with that work and could be done at the same time. But you could start by observing and comparing non-living things, for example sheets of paper, parachutes, kites and airplanes. It can be useful to observe and compare things dropping, or falling through air. It begins to give pupils the idea that air must consist of small particles that are free to move, but nevertheless get in the way and push against things as they drop.
In Case Study 2, we read how a teacher uses a pupil’s question to get the class talking and thinking about how airplanes stay up. Activity 2 starts by getting the children observing using different languages, and then moves to a practical challenge where pupils’ thinking is revealed by what they do to solve a problem.
Case Study 2: What keeps a heavy airplane up in the sky?
When Paulina at Waribogo Primary School, Ghana, gave her pupils the chance to raise their own questions about air, Bulus wanted to know what kept an airplane up in the air. Paulina got some advice from a colleague, Ernest, at a nearby secondary school. Read his advice in Resource 3: What lifts an airplane?
Some of the demonstrations and activities he suggested really puzzled the pupils, especially the one where the table tennis ball could not be blown out of the funnel, no matter how hard Joseph tried. Yet tiny Befu could hit the roof by blowing through a tube of cardboard. What impressed Paulina most was that her pupils even suggested some changes to the ‘blowing under the paper bridge’ activity. What would happen if the bridge were the other way up? She praised them and let them test this out as well.
At the end of the lesson, they gave a short presentation to the head teacher about this question.
Activity 2: The exciting slow paper race
- First, demonstrate the ‘fast paper race’. Stand on your chair or table and hold high two identical sheets of A4 paper, labelled A and B.
- Ask pupils to guess which one will reach the ground first. Just before you drop them, crumple paper B into a tight ball. Repeat the action a few times asking the pupils to observe and compare carefully.
- Draw a two-column table on the board to record their observations and descriptions of how each paper fell. Pupils use the languages they know to describe the movement of the papers. This makes an excellent multilingual activity and gives you a chance to assess your pupils as they think and talk.
- Finish with the ‘slow paper race’. Give pairs of pupils identical long strips of paper about 30 cm x 5 cm. Their challenge is to modify (change in some way) the paper, so that it falls very slowly through the air. Which design falls slowest?
(Resource 4: The slow paper race gives additional ideas and advice.)