4th Class

     Measurement   We need to measure different things in our daily life like length of objects, height, weight (fruits, vegetables, etc.) quantity of milk, water and so on.              Measurement of Length In early days, people used body parts to measure lengths.               Cubit                                         Hand span The metre is what we normally use for measuring lengths. Smaller lengths an measured in centimetres. Metre is written as m and centimetre as cm.   Measurement of Mass Mass tells us how heavy or light an object is. We use weighing scales to find the mass of an object. Just as we use metre for measuring more...

     Introduction   Living things on the earth are mainly divided into two major groups, the plant kingdom and the animal kingdom.                                                          Plant Kingdom                                                       Animal Kingdom   The plant kingdom comprises of all the green plants present on the land, water and even those which are non-green in colour. The green colour of the plant is due to the presence of chlorophyll, which aid in photosynthesis. Nature has a wide variety of plants. Each variety has its more...

     Photosynthesis   Photosynthesis is the process by which plants make their own food. It the process of converting carbon dioxide into organic compound, especially sugar using water and sunlight. Oxygen is a by-product of this process. Photosynthesis is vital for life on earth, as it maintain the normal level of oxygen in the atmosphere. All life depends on photosynthesis directly as a source of energy or indirectly as the ultimate source of the energy in their food. Photosynthesis is also the source of carbon in all the living form. Most of the plants have green pigment called, chlorophyll, in their leaves. Chlorophyll gives the green colour of the leaf, helps in photosynthesis. It is the chlorophyll that helps the plants to trap the energy from the sunlight for making their food. Oxygen, which is produced during photosynthesis is essential for all living organisms more...

   Respiration   Like all living organisms, plants also go through the process of respiration. This process is essential, as it provides energy and the carbon escalation for growth and maintenance. Plants consume about 25 - 75% of all the carbohydrates produced in photosynthesis.  Sugar + Oxygen  Carbon dioxide + Water + energy.                         Plants, like other living things use atmospheric oxygen to breakdown glucose (food produced in photosynthesis) into carbon dioxide and water for the release of energy. This energy is used for its growth and maintenance. In plants, all living cells of root, stem and leaf take in oxygen independently and give out carbon dioxide and water. Hence in plants, there is little transport of gases, from one part to another, occurs Respiration in plants occur at a much more...

      Aquatic Plants    Aquatic plants are those which live in or on the water. Aquatic plants are also called hydrophytic plants. These plants have evolved special features like air sacs for flotation, increased number of stomata, smaller feathery and specialized roots to take in oxygen. Aquatic plants are of three main types.          Floating Plants These plants are like sponge. There are numbers of empty spaces throughout their body, which is filled with air. This makes the plant light enough to float in the water. For example, duckweed, water hyacinth.      Water Hyacinth              Fixed Plants These plants have roots fixed to the mud at the bottom of the pond. They have thin, long, hollow more...

       Non-Green Plants   Plants which do not have chlorophyll are called non-green plants. They cannot make their own food and usually absorb food from other plants, dead animals or stale food. One type of non-green plant is fungus. Mushroom, toadstools and mould are also example of non-green plants.       Non-Green Plant                   Fill in the blank with the appropriate answer. Non-green plants have ____ type of nutrition. (A) Autotrophic nutrition (B) Heterotrophic nutrition (C) Symbiotic nutrition (D) All of these (E) None of the above   Answer: (b)           Name a non-green edible plant that can't prepare their own food but provide us with high more...

       Terrestrial Plants   Plants that grow on land are called terrestrial plants. Terrestrial plants are of different types depending on the condition they grow in.              Plants on Mountains Plants on mountains and hills are tall, straight and have slopping shape to make the snow fall off easily. They are usually flowerless and have cones with seeds inside them. The leaves are needle like with waxy coating. For example, fir, deodar, pine, cedar, small flowerless plants like ferns, lichens and mosses etc.                                                                                     Pine tree                                                   Deodar tree     more...

LEARNING OBJECTIVES

• apply the knowledge of series completion and odd one out.
• use coding decoding.
• understand mathematical reasoning.
• study mirror image and embedded figures.
• use different patterns, number ranking and alphabetical tests.

  Real Life Example Beautiful patterns surround us. You can see them on trees, clouds, on bodies of water. You can even see them on plants, on animals and on our very skin. The very tips of our fingers prove just that. There is also no doubt that patterns are just as mysterious as they are beautiful. In fact, there are some patterns that are so perfect that they self – replicate.   QUICK CONCEPT REVIEW Odd One Out In odd one out we need to identify the more...

LEARNING OBJECTIVES This lesson will help you to:—

• collect data from different sources.
• record data using tally masks.
• prepare tables for recording data.
• represent data in terms of pictograph choosing appropriate unit for displaying data.
• represent data in terms of bar graphs choosing appropriate unit for displaying data.
• represent data in terms of pie-chart.
• recognize patterns in the data.
• draw inferences from the data.

  Real Life Example

• Data handling is widely used in collection of scores of students in various exams and marking ranks to the students.
• Pictographs are used by newspapers and magazines to attain the attention of the readers.
• Classrooms are often full of pictographs, for example, charts for lunch, more...

LEARNING OBJECTIVES This lesson will help you to:—

• outline the boundary of a shape.
• identify shapes like square, rectangle and circle and separate it from other shapes.
• explore intensively the area and perimeter of simple shapes.
• estimate the area and perimeter of a shape.
• find the area and perimeter of a shape using grid method.

  Real Life Examples

• Knowledge of area and perimeter helps in installing a garden.
• The perimeter can be used to calculate the length of fence required to surround a yard or garden.
• The perimeter of a wheel (its circumference) describes how far it will roll in one revolution.
• The amount of string wound around a spool is related to the spool’s perimeter.
• Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape.
• Area is the amount of paint more...