3rd Class

    Leibnitz Calculator     It was a digital mechanical calculator invented by German mathematician and philosopher Gottfried Wilhelm Leibnitz around 1672 and completed in 1694. Pascal developed the machine because he had to help his father with his work as tax receiver. This was an improvement over the Pascaline. This machine was also able to perform multiplication and division and all the mathematical calculations. Leibnitz's machine used a stepped cylinder. This machine was also called stepped calculator.                Leibnitz calculator was a calculating device. It was the improved form c which one of the following devices? (A) Abacus                                                          (B) Napier's bones (C) Pascaline                                                      (D) All of these (E) None of these     Answer: (C) Explanation Correct Option: more...

     Mechanical Device - The Pascaline     The calculating machine Pascaline was a mechanical device which was designed and built by the French mathematician-philosopher Blaise Pascal between 1642 and 1644. It could add and subtract numbers. It performed multiplication by repeated addition and division by repeated subtraction. It was also called Pascal's calculator. This machine was capable of doing addition and subtraction with a high speed. It worked on the principle of clockwork mechanism. This machine consisted of chain and toothed wheels. The teeth on each wheel represented numbers from 0 to 9 from right to left and each wheel represented units, tens, hundreds, thousands, ten thousands and so on. This device was used everywhere and became very popular in a short period because of its speed and accuracy.            more...

        Information about- Napier's Bone     Napier's bone is an abacus created by John Napier in 17 AD for calculation of products and quotients of numbers. Sir John Napier was a great mathematician of Scotland. This was a manual device. Napier's bone is also called Napier's rod. It was made up of bones and rods. It was capable of doing all the four mathematical operations - addition, subtraction, {multiplication and division. Using the multiplication tables embedded in the rods, multiplication can be reduced to addition operations and division to subtractions.                  Napier's bones was created by John Napier. From which country he belonged? (A) England                                                         (B) Sweden (C) France                                                                           (D) Scotland more...

    History of Computers     History of computing hardware goes back to many years. The modern computer is the result of continuous process of developing a machine like computer. Finally the computer was developed. John Von Neumann was the man who developed the first computer called ENIAC (Electronic Numerical Integrator and Computer) in 1946. It used to do mathematical operations and store data. Before its invention, a variety of other machines were |used for calculation. The history of computers started from the ancient period when wan used stones, beads, sticks and bones for calculation work. But as the man developed, he felt the need for calculation devices and this need of devices finally led to the development of computer. The earliest calculation device was invented in 500 BC.          

       First Calculating Device - The Abacus     It was the first calculating device which was invented by the Chinese. It is also called a counting frame and is a calculating tool used primarily in parts of Asia for performing arithmetic processes. The abacus is a manual device. It is typically constructed of various types of hardwoods and comes in varying sizes. The frame of the abacus has a series of vertical rods on which a number of wooden beads are allowed to slide freely. A horizontal beam separates the frame into two sections, known as the upper deck and the lower deck. It is used to count, add and subtract by moving the beads up and down. These beads are marked as unit, tens and hundreds and so on from top to bottom. The beads are moved according to set rules more...

     Non Renewable Resources   Nonrenewable resources cannot be regenerated. Oil, coal, natural gas, etc. are some examples of nonrenewable resources.                                                                  Coal                                           Liquefied Petroleum Gas (LPG)              Some Important Natural Resources Nature has given us many important resources for our use. Some of them are given below.            Sun The sun provides light and warmth to the more...

     Introduction   Nature gives us many things. For example forest, sun, wind, water, minerals, land, etc. The things that we get from nature is called natural resources. Natural resources are classified into: (i) Renewable (ii) Nonrenewable resources.        Renewable Resources Renewable resources are that resources, which we can use repeatedly and renew. For example, 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, petrol. Abiotic: The resources that we derive from non-living things. For example, land, water, air etc.                                             more...

     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 when force is applied. For example, 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 There are three types of motion. They are uniform motion, non-uniform motion and circular motion.            Uniform Motion If a body travels equal distance in equal interval of times then it is called uniform motion. For example, a car travels first 30 kilometres in one hour and next 30 kilometres again in one hour more...

       Matter   Every day we see various things around us. Some of them are heavy, for example, computer. Some of them are light, for example, your pencil. This is because, different objects have different masses. The mass of an object tells us whether an object is heavy or light, or how much heavy or light. Every object also occupies space. For example, books in your school bag, pencils in your pencil box, water in water bottle, all 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 stages of matter.              Solid Objects like books, pen, pencil, cricket bat, doll, tiffin box, school bag etc. have a fixed shape. They more...

   First Aid   If any accident happens by chance, first thing, to do is to provide help to the person met with accident to save his precious life. Such help is called first aid. In this chapter, we’ll learn about the type of first aid, which should be provided to the injured person, in different situations.          Bone Fracture Injury Look at the following picture of bone fracture injury: Bone fracture means a bone has been broken. The affected area swells up and it pains a lot, as the supply of the blood to the affected part get blocked.            First Aid in Case of Fracture Do not let the affected area to move. Support the injured portion with more...