In Singapore, we use the framework CER (Claim, Evidence and Reasoning) to guide their students to answer Open-ended Questions. Children naturally have lively, inquisitive minds, but perhaps due to their enthusiasm, they find it hard to structure their thoughts and answer to the point. CER is a good way for students to examine diagrams and charts, pick out the pertinent information and link it to relevant Science concepts.
In a nutshell, this is what CER refers to:
Claim - the answer/conclusion about a problem
Evidence - Scientific data (information/clues)in the question that is appropriate to support your claim
Reasoning - Justification that connects evidence to the claim using scientific concepts
Application of CER
Characteristics of Living Things
- A fish was placed in a bowl filled with water and fed with food. The top of the bowl was covered with a cardboard. Would the fish survive after a few hours? Why?
A: No. Due to the cardboard, the fish did not have enough air. The fish will need air to survive.
Plants
2. Based on the diagram, which plant, A or B, is a flowering plant? Explain your answer.
A: Plant A. Plant A has fruits. Fruits come from flowers in flowering plants.
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Which plant, X or Y, will die after a week? Explain your answer. A: Plant Y. There is no water for Plant Y to take in through the roots. Plants need water to survive.
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After a few days, Jamal observed that one of the plants had grown taller as compared to the other. Which plant, X or Y, had grown taller? Explain why. A: Plant Y. The clear glass tank lets light pass through, so Plant Y can receive sunlight. Plant Y can thus photosynthesise in the presence of sunlight and grow taller.
Animals
5. Kelsie came across Animal P in the forest. She classified it as an insect. Her teacher said that she had classified it wrongly. Give two reasons why Kelsie was wrong.
A: Firstly, animal P has 4 pairs of legs but insects have 3 pairs of legs.
Secondly, animal P has 2 body parts but insects have 3 body parts.
Fungi
6. On which bread, A or B, would mould grow on first?
A: Bread B. There is moisture in the cotton wool for mould to grow on B but not on A. Mould needs water to grow.
- Ann’s mother told her to put a handbag in an air-tight plastic bag so that mould would not appear. Explain the reason for her mother’s suggestion. A: There will be no air for the mould to grow. Mould needs air to survive.
Materials
8. Based on the information above, which string, L, M or N is the strongest? Explain your answer.
A: String N. String N had the most metal balls added before the string broke, compared to strings L and M.
9: Based on the results above, which material, D, E or F, is the strongest? Give a reason for your answer.
A: Material F. Material F supported the most weights before it broke, compared to Materials D and E.
Digestive System
10: Which organ, P, Q, R or S represents the large intestine? Give a reason for your answer.
A: Organ R. It shows the least amount of water in the food leaving the organs. The large intestine is where water is removed from undigested food.
Magnets
11: An object is brought near one end of a suspended magnet. The object and the magnet repel. What can you conclude about the object? Why?
A: The object is a magnet. Since the object is repelling the magnet, the like poles of the object and the magnet are facing each other. Like poles repel.
12: Magnet A is hung from a spring. Object B is then placed on the ground directly below Magnet B. It was observed that the spring became compressed. What do you think Object B is? Why?
A: Object B is a magnet. Because the spring was compressed, Object B must have repelled Object A. Only a magnet will repel another magnet.
13: In which set-up can the iron nail attract more steel clips? Explain your answer.
A: Set-up B. Set-up B had more coils of wire around the iron nail than Set-up A. The more coils of wire around an iron nail, the stronger the electromagnet.
14: From the observation above, which magnet, A, B, C or D has the greatest magnetic strength? Give a reason for your answer.
A: Magnet D. Magnet D attracts a paper clip even though it is furthest away from the clip among all the magnets. The longer distance at which a magnet attracts paper clips, the stronger it is.