Story: Dev finds an old wooden frame with coloured beads in his grandfather’s cupboard. ‘This is an Abacus,’ says Dadaji. ‘Long before computers, people used tools like this one to count and calculate. Would you like to know how we went from beads on a wire to the laptop on your desk?’ Dev nods, and Dadaji begins the story of the amazing journey of computers.

Since ancient times, people have invented tools for calculation. Early humans tied knots in ropes and carved marks on clay to keep records. They also used fingers, toes, pebbles, stones, sticks, knotted strings and bones to count.

The first real step towards computing was the invention of the Abacus, around 3000 years ago in China. It is a wooden frame with beads on parallel wires, used to do simple calculations like addition and subtraction at a fast speed. The Abacus is still used in some schools today as an aid in teaching the numeral system.

In 1642, a mathematician named Blaise Pascal invented a calculating machine called the Pascaline Adding Machine, when he was only 19 years old. Numbers were fed into the machine by dialling them on wheels. The Pascaline is believed to be the first mechanical calculator in the world, but it could perform only addition and subtraction.

Earlier, in 1617, John Napier had invented a calculating device called Napier’s Bones. It was able to perform addition, subtraction, multiplication and division.

In 1672, a mathematician named Gottfried Wilhelm Leibniz expanded Blaise Pascal’s ideas and invented the digital mechanical calculator called the ‘Step Reckoner’. It was the first calculator that could perform all four arithmetic operations: addition, subtraction, multiplication and division.

In 1822, a mathematician named Charles Babbage developed a steam-driven calculating machine the size of a room, which he called the Difference Engine. It consisted of a series of gears and levers that could be programmed to perform one specific calculation. But even after working on it for 10 years, this machine never became a reality.

In 1833, Babbage invented a machine called the Analytical Engine, the first-ever working model of a mechanical computer: a fully program-controlled machine. It also included integrated memory, program flow control and an ALU (Arithmetic Logic Unit). This is why Charles Babbage is known as the ‘Father of Computers’.

The instructions given to Babbage’s Analytical Engine were in the form of binary numbers, 0s and 1s, and the first person to introduce this concept was Lady Ada Lovelace. Since she was the first to introduce the concept of programming, she is known as the ‘First Computer Programmer’.

Herman Hollerith, an army engineer, built an electromechanical device called the Tabulating Machine in 1890. The machine read and stored data from punched cards. After its success, Hollerith formed a Computing Tabulating Recording Company to sell his machine. Later, in 1924, his company became part of the International Business Machines Corporation, today popularly known as IBM.

After these early calculating machines, the present computer took its shape over five generations.

First Generation (1940s): In 1944, Prof. Howard Aikens built Mark-I, the first electro-mechanical computer. It used punched cards and a typewriter for input and output, was 50 feet long, 8 feet high, weighed 5 tons, and could add, subtract, multiply, divide and refer to previous results. In 1945, ENIAC (Electronic Numerical Integrator and Computer), built by John Mauchly and Presper Eckert, became the first electronic general-purpose digital computer. It had over 18,000 vacuum tubes, was 1000 times faster than Mark-I, consumed almost 200 kW of power, and had no internal storage. In 1951, the same two inventors built UNIVAC (Universal Automatic Computer), with 5200 vacuum tubes, which could handle both numeric and textual information. First generation computers were huge, very expensive, and made of vacuum tubes.

Second Generation (1950s): After 1955, transistors and magnetic tapes changed the image of the electronic computer. Manufacturers began offering page printers, cathode ray-tube displays and card feeders. These computers were smaller, faster, more reliable and more energy-efficient, and used magnetic tapes to store data.

Third Generation (1960s): The invention of Integrated Circuits (IC) led to smaller computers with better functioning and more storage. They were sometimes called minicomputers: smaller, cheaper, more affordable and more dependable than before.

Fourth Generation (1970s): Very Large Scale Integration (VLSI) placed thousands of transistors on a single chip called a microprocessor, so these were sometimes called microcomputers. IBM released its first desktop PC, using the Intel 8088 chip as CPU; in 1983 it introduced the PC-XT with more memory and hard drive space; and in 1985, Microsoft released the first version of Microsoft Windows. Fourth generation computers were small enough for an office table, used a hard disk to store data, and introduced the GUI (Graphical User Interface) operating system.

Fifth Generation (present, after 1986): This generation is based on Artificial Intelligence (AI) and is still developing. In 1997, Intel introduced the MMX microprocessor, designed to improve game and multimedia performance. The goal of fifth-generation computing is to develop devices that respond to natural language input, like chatbots, autocomplete, autocorrect, spellcheck and search engines.

A computer has several useful characteristics. Speed: a computer can process millions of instructions within a few seconds; its speed is measured in MIPS (Millions of Instructions Per Second). Accuracy: a computer gives a high degree of accuracy, and every calculation is performed with the same accuracy. Diligence: a computer can work for hours without any breaks or boredom; it does not get tired.

Storage capacity: a computer can store a very large amount of data in its hard disk, and devices like CDs, DVDs and flash drives store even more. Versatility: computers can perform many different kinds of tasks; at one time, you can type a document while also listening to a song. Compactness: with regular advances in technology, computer size keeps decreasing.

Reliability: a computer does not make mistakes on its own; if the input is correct, it always gives the relevant answer. Power of remembering: the data stored in a computer can be recalled at any time.

A computer is a versatile machine, but it also has limitations. Lack of decision-making ability: a computer does not have a brain like human beings, and cannot take a decision on its own; it can only perform the tasks it is instructed to do. Lack of intelligence: a computer has zero intelligence of its own; it can only work as per the instructions given by human beings.

Lack of feelings and emotions: computers do not possess feelings or emotions like human beings, and cannot do anything on their own. Time taken in planning and programming: we must first choose the jobs to be computerised, and then proper planning and development of programs can take days, months and sometimes even years. Human Dependency: a computer is fully automated once switched on, but it cannot switch itself on; it cannot work completely on its own without human assistance.

Image prompt: Flat illustration of an Indian child sliding coloured beads on a wooden abacus frame, bright colours, no text.

The Abacus uses beads on wires to do simple addition and subtraction.

Key idea: It was invented in China about 3000 years ago.

Image prompt: Flat illustration of a young Blaise Pascal in 17th-century clothing dialling numbers on a small brass box machine with wheels.

Blaise Pascal built this mechanical adding machine in 1642, at the age of 19.

Key idea: It could only add and subtract.

Image prompt: Flat illustration of a large room-sized Victorian machine made of brass gears and levers, with Charles Babbage standing beside it.

Charles Babbage designed this fully program-controlled mechanical computer in 1833.

Key idea: It is why Babbage is called the ‘Father of Computers’.

Image prompt: Flat illustration of Lady Ada Lovelace in Victorian dress, writing a list of 0s and 1s on paper beside a gear-driven machine.

Ada Lovelace wrote the first set of instructions, in binary numbers, for the Analytical Engine.

Key idea: She is called the ‘First Computer Programmer’.

Image prompt: Flat illustration of an old punched-card machine with a card reader and a dial panel, Herman Hollerith standing beside it.

Herman Hollerith’s 1890 machine read and stored data from punched cards.

Key idea: His company later became part of IBM in 1924.

Image prompt: Flat illustration of a huge room filled with cabinets of blinking vacuum tubes and wires, two operators adjusting switches.

ENIAC (1945) was the first electronic general-purpose computer, with over 18,000 vacuum tubes.

Key idea: First generation computers were huge, costly and used vacuum tubes.

Image prompt: Flat illustration of a tiny silicon microprocessor chip held between two fingers, with a giant old computer faded in the background.

A microprocessor places thousands of transistors on a single small chip.

Key idea: Fourth generation computers became small enough for an office table.

Image prompt: Flat illustration of an Indian student using a laptop that shows a friendly chatbot face on its screen, speech bubbles with question marks.

Fifth generation computers use Artificial Intelligence to understand natural language, like chatbots and search engines.

Key idea: A computer still has no feelings of its own; it only follows instructions.

Dev finds his grandfather’s old wooden abacus in a cupboard in their Mumbai flat. He slides the colourful beads along the wires, trying to make the number 37. His grandfather explains that before computers, this simple tool, invented in China about 3000 years ago, was used for addition and subtraction. Dev is amazed that something so simple was once so important.

Questions

1. What is the name of the old counting tool Dev finds?
2. About how long ago was the Abacus invented, and where?
3. What two operations can an Abacus perform?
4. Name one other early counting tool used before the Abacus.
5. Why might Dev’s grandfather still remember how to use an Abacus?

Priya’s teacher in Pune gives the class a project: find out who is called the ‘Father of Computers’ and who is called the ‘First Computer Programmer’. Priya reads that both people worked on the same machine, the Analytical Engine, but did very different jobs. She makes two posters, one for each inventor, to present to her class.

Questions

1. Who is called the ‘Father of Computers’, and why?
2. Who is called the ‘First Computer Programmer’, and why?
3. In which year was the Analytical Engine invented?
4. What number system did Lovelace use to write her instructions?
5. Why did Priya make two separate posters instead of one?

On a school trip to a technology museum in Mumbai, Arjun sees a huge old machine behind glass, covered in blinking lights and switches, with a sign that reads ‘ENIAC, 1945’. The guide explains it had over 18,000 vacuum tubes and filled an entire room, yet it was 1000 times faster than the computer before it. Arjun compares it to his father’s slim laptop and cannot believe how much computers have changed.

Questions

1. What is the name of the machine Arjun sees, and in which year was it built?
2. What were ENIAC’s circuits made of?
3. Which earlier machine was ENIAC 1000 times faster than?
4. Name one feature of first-generation computers that made them hard to use.
5. Why is Arjun amazed when he compares ENIAC with his father’s laptop?

Neha asks her family’s smart computer assistant to help her decide what to wear to her cousin’s wedding. The assistant can tell her the weather and show her pictures of outfits, but it cannot tell her how she will feel in each one, or which colour will make her grandmother smile the most. Neha realises she must make this decision herself.

Questions

1. What task did Neha ask the computer to do?
2. Why could the computer not make this decision for her?
3. Name one thing the computer could still help Neha with.
4. Which limitation of a computer does this story mainly show?
5. Why is it important for Neha to understand this limitation?

The principal of Riya’s school wants a new computer program that will mark attendance automatically using a tablet. The computer teacher explains that this cannot be done overnight: the team must first plan exactly what the program should do, then write and test the program carefully. The principal is surprised to learn that this process may take several months.

Questions

1. What new program does the principal want for the school?
2. According to the computer teacher, can this program be built instantly?
3. Which limitation of a computer does this story describe?
4. Name the two main steps the teacher describes before the program is ready.
5. Why do you think careful planning is important before building a computer program?