3rd Class

                                                                       Human Body   Our Body   Body parts   Human body consists of different parts. All of these parts have specific functions to perform. For example, we can see with the help of eyes and walk with the help of legs.   Flue Sense Organs You know that we have five sense organs, which helps us to feel and know the world around us. Our sense organ and their functions are as follows:   Tongue We can taste with the help of tongue. We can taste whether the food we eat is sweet, sour or salty with the help of taste buds located on the tongue.   Ear We can hear the sounds with the help of ear. We can hear different sounds.   Eyes We can see with the help of eyes. Whenever we see more...

                                                                           Matter   Matter We see various things around us. Some of them are heavy, for example, bicycle. Some of them are light, for examples, your pen. This is because, different objects have different masses. The mass of an object tells us whether an object is light or heavy. Every object occupies space. Anything which has mass and occupies space is called matter. Matter exists in three different forms: (i) Solid (ii) Liquid (iii) Gas These three forms of matter are called the states of matter   Solids Objects like books, bricks, pencil, mobile, tiffin box, etc. have a fixed shape. They do not change their shape if we move them from on container to another. They are called solid objects.   Liquids Substances such as water, milk, oil, etc. can flow easily and change their shape according to the shape of container they are more...

                                                                 Environment   Environment Our environment includes living things like plants and animals and non-living things like air, water, soil, sunlight, weather, seasons, etc. All these are the components of environment.   Air Air is all around us. Air contains water in the form of water vapour. It also contains dust particles, gases like oxygen, hydrogen, carbon dioxide, etc.   Water Water is very important for life on earth. Rivers, glaciers and lakes are sources of fresh water on earth. Seas and oceans contain salt water.   States of Water Water occurs in all the three states. Ice is the solid form of water. When ice melts, it changes into liquid form. When water is heated or boiled, it becomes steam. Steam is also called water vapour.   Water Cycle Water from rivers and ponds goes up as water vapour in day time, when it more...

                                                                Motion and Transport   Motion Movement of an object from one place to another is called motion. We see many things around us are in motion. Motion takes place whenever force is applied. For example, when a boy throws a ball, movement of the ball takes place due to the force exerted by the boy.   Boy exerts force to throw ball   Different Types of Motion These are three types of motion.   Uniform Motion If a body travels equal distance in equal interval of time then it is called uniform motion. For example, a car travels first 30 kilometres in one hour and next 30 kilometres again in are hour and so on then we can say that car is in uniform motion.   more...

                                                                         Natural Resources   The things that we get from nature are called natural resources. Nature gives us many things. For example, forest, sun, wind, water, minerals, land, etc. this is classified into. (i) Renewable resources (ii) Nonrenewable resources   Renewable Resources Renewable resources are those resources, which we can use repeatedly. For example, trees, soil, solar power, wind power, etc. On the basis of the origin of these resources, they can be classified into: Biotic: The resources that we derive from living organisms. For example, tree. Abiotic: The resources that we derive from non-living things. For example, land, water, air, etc.   Non Renewable Resources Nonrenewable resources cannot be regenerated. Oil, coal, natural gas, etc. are some examples of nonrenewable resources.   Forests Forests are renewable natural resources. They prevent floods conserve soil by replenishing the minerals and give oxygen to the atmosphere.    more...

                                                                    Our Universe   Our Universe Our universe is a large and unimaginable expansion of gases, dust, stars, planets, etc.   Stars Stars are the huge balls of fire that twinkle in the night. They are very far away from us. A telescope is used to see the stars, the moon and the planets clearly.   Sun Sun is a star. It is a huge ball of fire that gives us light and heat. Sun is also the head of a big family called solar system. Solar system consists of sun and eight planets along with their satellites.   Planets There are eight planets in the solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. There is also a dwarf planet in the solar system known as Pluto. A planet revolves around the sun in a fixed path.   more...

                                                                  Our Safety and First Aid   Our Safety and First Rid Our body is like a machine performing different functions like walking, running and eating, etc. We should take care of ourselves by keeping safe from illness and injury. We should follow safety rules at home, school, on the road and in the playground.   Some Safety Rules to be followed at Home

• Do not leave your toys, bags and books lying on the floor. You might trip over them and injure yourself.
• Be careful while walking on wet bathroom floors. You might slip on the floor and get hurt.
• Don’t use water near electrical appliances. Don't touch them with wet hands. You might get an electric shock.
• Don't jump on the stairs. You might fall down.
• Don't play with knives and scissors.

  Safety Rules at School

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  Number Sense and Numeration   Introduction Everything is counted by numbers. Numbers are the symbolic representation of counted objects.   Types of Number Natural Numbers Counting numbers are known as natural numbers. For example, natural numbers (N) = {1, 2, 3, 4, 5 .... to infinite}   Whole Numbers Counting numbers including 0 are known as whole numbers. For example, whole numbers (W) = {0, 1, 2, 3, 4 ..... to infinite}   Even Number Numbers which are exactly divisible by 2 are called even numbers. For example: {2, 4, 6, 8, etc.}   Odd Numbers Numbers that are not exactly divisible by 2 and leaves remainder are called odd numbers. For example: {1, 3, 5, 7 etc.}   Operations on Numbers Place Value Place value of digits of a number is their position in the number. For example, place value of 2 more...

                                                                    Fractions   Introduction The Latin name of fraction is fractus. It means broken. It has two parts, upper and lower part. The upper part is called numerator and lower part is denominator.   Fractions in Its Lowest Term The lowest term of a fraction is obtained by dividing numerator and denominator with common divisor. The lowest form of the fraction \[\frac{6}{9}\] is\[\frac{2}{3}\]. The lowest term of the fraction g is obtained by dividing the numerator and denominator with a common divisor 3.  

• Example

What is lowest term of the fraction\[\frac{45}{65}\]? (a) \[\frac{9}{13}\]                     (b) \[\frac{2}{3}\] (c) \[\frac{5}{9}\]                      (d) All the above (e) None of these Answer (a) Explanation: Common divisor of 45 and 65 is 5. Therefore, dividing 45 and 65 by 5, we get\[\frac{9}{13}\].

• Example

Find the simplest form of the shaded parts of more...

                                                           Time and Calendar   Introduction SI unit (Standard International unit) of time is second. We know that 60 seconds = 1minute and 60 minutes = 1 hour. Calendar that we use today is actually adopted from gregarine calendar.   Time Indicating Watch Watch indicates time. The face of watch is called its dial. Dial of a watch is divided into twelve big divisions from 1 to 12. The gaps among the numbers are divided into five small divisions each of which indicates a minute.    

• Example:

A watch shows the time of a quarter past 3. Which one of the following is correct for the time as quarter past 3? (a) \[~3\text{ }:\text{ }15\]                     (b) \[3\text{ }:\text{ }45\] (c) \[2\text{ }:\text{ }45\]                      (d) \[3\text{ }:\text{ }25\] (e) None of these more...