# EARLY MECHANICAL COUNTING/CALCULATING DEVICES

**Subject** :

**Computer Studies / Information Communication Technology ICT **

**Topic** :

**EARLY MECHANICAL COUNTING/CALCULATING DEVICES**

**Class** :

SS 1

**Term** :

FIRST TERM

**Week** :

Week 2

**Reference Materials : ** .

- ONLINE MATERIALS
- SCHEME OF WORK
- TEXTBOOKS

**Instructional Materials** :..

- Computer Studies
- Online Resources

**Previous Knowledge : **

The pupils have previous knowledge of

### **INTRODUCTION TO DATA PROCESSING**

that was taught as a topic in their previous lesson

**Behavioural Objectives :** At the end of the lesson, the pupils should be able to

- define some early counting devices
- say the importance of the early counting machines
- list the progress made by the scientists that invented these early counting machines
- List any four early counting devices.

**Content** :

**WEEK TWO**

**TOPIC: HISTORY OF COMPUTING**

**EARLY MECHANICAL COUNTING/CALCULATING DEVICES**

- Abacus
- Slide rule

**EARLY ELECTRO-MECHANICAL COUNTING DEVICES**

1. The first known mechanical device for counting was the abacus, which was invented in Babylonia in around 2400 BC.

2. The abacus is a frame with a series of beads that can be moved up and down to represent numbers.

3. The first known mechanical device for adding was the Napier’s bones, which was invented by John Napier in 1617.

4. Napier’s bones are a set of rods with numbers inscribed on them that can be used to perform addition and subtraction.

5. The first known mechanical device for multiplying was the Leibniz wheel, which was invented by Gottfried Leibniz in 1673.

6. The Leibniz wheel is a cylindrical device with teeth that can be used to multiply two numbers by turning the wheel.

1. The Abacus

The abacus is a counting device that was used in ancient times. It consists of a frame with beads that are moved around to represent numbers. The abacus is still used in some parts of the world today.

2. The Napier’s Bones

Napier’s bones is a mechanical device that was invented by John Napier in the early 17th century. It consists of a set of rods with numbers inscribed on them. The rods are arranged in such a way that they can be used to perform mathematical operations.

3. The Pascaline

The Pascaline is a mechanical calculator that was invented by Blaise Pascal in the mid-17th century. It consists of a series of gears that are used to add and subtract numbers. The Pascaline was the first mechanical calculator to be mass-produced.

4. The Stepped Reckoner

The Stepped Reckoner is a mechanical calculator that was invented by Gottfried Leibniz in the late 17th century. It is similar to the Pascaline, but it uses a system of wheels and dials instead of gears. The Stepped Reckoner is capable of performing more complex operations than the Pascaline.

**EARLY ELECTRONIC COUNTING DEVICES:**

- Herman Hollerith punch card
- John Von Neumann machine

Man has put in every effort to have better methods of calculations. As a result of man’s search for fast and accurate calculating devices, the computer was developed. Essentially, there are three kinds of calculating devices: manual, mechanical and automatic.

**ABACUS**

The first calculating device was probably Abacus. The Chinese invented it. It is still in use in some countries because of its simple operation. It is made up of a frame divided into two parts by a horizontal bar and vertical threads. Each thread contains some beads. It was used to calculate simple addition and subtraction.

**NAPIER’S BONE**

The need for a better calculating device was felt as time passed. John Napier, a Scottish mathematician, invented a set of eleven rods, with four sides each which was used as a multiplication tool. These rods were made from bones and this was the reason why they were called Napier Bones. The rods had numbers marked in such a way that, by placing them side by side, products and quotients of large numbers can be obtained.

**EVALUATION**

- Explain types of early counting devices.
- How does Abacus and Napier’s function.

**PASCALINE**

The first mechanical calculating machine was invented in 1642, by Blaize Pascal, a French mathematician. Numbers were entered by dialling a series of numbered wheels in this machine. A sequence of wheels transferred the movements to a dial, which showed the result.

Through addition and subtraction were performed the normal way, the device could perform division by repeated subtraction and multiplication by repeated addition.

**LEIBNITZ CALCULATING MACHINE**

Gottfried Wilhelm Von Leibnitz invented a computer that was built in 1694. It could add and after changing some things around, it could multiply. Leibnitz invented a special stepped gear mechanism for introducing the added digits and this is still being used.

**JACQUARD’S LOOM**

Jacquard’s loom was one of the first machines that were run by a program. Joseph Jacquard changed the weaving industry by creating a loom that controlled the raising of the thread through punched cards. Jacquard’s loom used lines of holes on a card to represent the weaving pattern.

**PUNCHED CARD**

During the years1920 and 1930, the punched card system developed steadily. A standard card was divided into 80 columns and 12 rows. Only one character could be represented in the 80 columns, thus providing a maximum of 80 characters per card. Punching one, two or three holes in any one column represented a character. Holes were punched into a blank card by a punch machine whose keyboard resembled that of a typewriter.

**CONCLUSION**

We have learnt about the various calculating devices and the various ways they perform their operations. We learnt also that Abacus was the first calculating devices.

**NUMBER SYSTEM (REVISION)**

To effectively use the computer, it is therefore necessary to know how data is represented and communicatedto it. There are different ways of representing data in the number system, namely:

- Decimal System
- Binary System
- Octal System
- Hexadecimal Number System.

**GENERAL EVALUATION**

- How does Abacus and Jacquard’s loom function?
- What type of operation can Pascaline perform?
- Explain the four number system.
- List any four early counting devices.

**WEEKEND ASSIGNMENT**

- Napier’s Bones had ……..A. 9 rods B. 11 rods C. 10 rods D. 12 rods
- Jacquard’s loom was used in the ……A. mechanical industry B. weaving industry C. food industry D. all of the above
- ……. was the first calculating device. A. Napier’s Bones B. Punched card C. Abacus D. Slide rule
- The octal number system has a radix of ……. A. 7 B. 10 C. 16 D. 8
- The Decimal Number is in Base ……A. 2 B. 8 C. 10 D. 16

**THEORY**

- Describe a standard Punch Card.
- Explain Decimal Number system.

**Presentation**

The topic is presented step by step

Step 1:

The class teacher revises the previous topics

Step 2.

He introduces the new topic

Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise

**GENERAL EVALUATION**

- How does Abacus and Jacquard’s loom function?
- What type of operation can Pascaline perform?
- Explain the four number system.
- List any four early counting devices.

**WEEKEND ASSIGNMENT**

- Napier’s Bones had ……..A. 9 rods B. 11 rods C. 10 rods D. 12 rods
- Jacquard’s loom was used in the ……A. mechanical industry B. weaving industry C. food industry D. all of the above
- ……. was the first calculating device. A. Napier’s Bones B. Punched card C. Abacus D. Slide rule
- The octal number system has a radix of ……. A. 7 B. 10 C. 16 D. 8
- The Decimal Number is in Base ……A. 2 B. 8 C. 10 D. 16

**THEORY**

- Describe a standard Punch Card.
- Explain Decimal Number system

**Conclusion** :

The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written. He or she does the necessary corrections when the need arises.