Science Class 4 Chapter 4 PDF

# Unit 3 - Materials ## 4. Clothes - Our Protectors Use Cordova Smart Class Software on the smart board in class to make learning enjoyable. Early humans had no idea of clothes. They used to cover their bodies with leaves of trees or animal skins. Later, they learnt about clothes. We wear clothe...

# Unit 3 - Materials ## 4. Clothes - Our Protectors Use Cordova Smart Class Software on the smart board in class to make learning enjoyable. Early humans had no idea of clothes. They used to cover their bodies with leaves of trees or animal skins. Later, they learnt about clothes. We wear clothes due to the following reasons: 1. Clothes make us look smart. 2. Clothes protect us from the heat of the Sun, cold, rain, dust and insect bite. 3. Clothes help us to identify the job of a person like doctor, lawyer, policeman, nurse and postman. **Recognise these people by their clothes and write their names in the spaces provided. You may use the Help Box.** | | | |---|---| | 1. | Policeman | | 2. | Student | | 3. | Soldier | | 4. | Doctor | | 5. | Dancer | | 6. | Lawyer | **I am a ...** 1. 2. Student 3. Dancer 4. 5. Doctor 6. **Do You Know?** The covered part of our body is usually fairer than the uncovered part because the uncovered part gets tanned by the sun rays. This shows that clothes protect us from direct sun rays. ## Clothes for Winter, Summer and Rainy Season We do not wear only one type of clothes for the whole year. We wear different types of clothes in different seasons. During winter, we wear woolen clothes. In summer, we wear cotton clothes. When it rains, we wear raincoats (that do not absorb water) over the usual dress. **Multiple Choice Questions (MCQs)** **Tick (✔) the correct answers.** 1. Clothes protect us from (a) heat ✔ (b) diseases (c) animals 2. We wear cotton clothes (a) in winter (b) in summer ✔ (c) when it rains ## How clothes are made Clothes are made from different types of cloth materials or fabrics. The fabrics are made by weaving the fibres. Fibres are long and fine threads. There are two types of fibres - natural fibres and synthetic fibres. ### 1. Natural Fibres The fibres obtained from natural sources like plants and animals are called natural fibres. Cotton, wool and silk are examples of natural fibres. We get cotton from cotton plant. We get wool from sheep. We get silk from silkworms. ### 2. Synthetic Fibres The fibres made from chemicals by humans are called synthetic fibres or human-made fibres. Nylon, polyester and rayon are examples of synthetic fibres. The clothes made up of synthetic fibres are generally wrinkle-free. Some are waterproof and some dry very quickly. Synthetic fibres are stronger than the natural fibres. ## Care of clothes Proper care of clothes keeps them in good condition for a long time. We can take care of our clothes in the following ways: 1. We should always use a good quality soap and detergent to wash clothes. 2. We should wash, dry and iron the clothes properly. 3. We should wash woollen clothes with liquid detergents that are made especially for woollen clothes. 4. We should give delicate and expensive woollen and silk clothes for dry cleaning. 5. We should wrap silk and woollen clothes in a cotton cloth and then store them with dried neem leaves or naphthalene balls. It will protect them from insects like moth and silver fish. **Do you know?** Silver fish is a wingless insect, not a fish. **Key Words** - Natural fibres: fibres obtained from plants or animals - Synthetic fibres: fibres made from chemicals by humans