Impact lines focus on students number sense and their understanding of directed numbers.
Provide students with or allow the students to create a list of advantages and disadvantages, on a particular concept/ topic . The students then work together and discuss which will have the largest positive and negative impact.
5 would be the largest positive impact and -5 would be the largest negative impact. As a challenge students should work out that 0 means the event has no impact at all on the topic.
Advantages and Disadvantages of Hydropower
- Once a dam is constructed, electricity can be produced at a constant rate.
- The lakes water can be used for irrigation purposes.
- When in use, electricity produced by dam systems do not produce greenhouse gases.
- The build-up of water in the lake means energy can be stored until needed.
- The lake that forms behind the dam can be used for water sports and leisure.
- Dams are extremely expensive to build. High cost means they must operate for decades to become profitable.
- Building dams can affect the water supply to towns and villages.
- Towns and villages need to be flooded, meaning people will lose their homes and natural environments destroyed.
- Building a large dam alters the natural water table level.
- Dams have been known to breach. This has subsequently led to death