NUMBER BASE SYSTEM WEEK: 9 JSS 2 Computer ICT

WEEK: 9

DATE: 4^{th –} 8^th November, 2024

CLASS: JSS 2

SUBJECT: INFORMATION TECHNOLOGY

LESSON TITLE: NUMBER BASE SYSTEM

SUBTITLE (IF ANY):

PERIOD: TWO

DURATION: 80 MINUTES

LEARNING OBJECTIVES: By the end of this lesson, students should be able to:

State the basic of number system
Convert from one base to the other

KEY VOCABULARY WORDS: binary, octal, hexadecimal.

RESOURCES AND MATERIALS: Comprehensive computer studies for basic education book 3 by A.S. Omotuyole, Computer connected with internet and projector.

BUILDING BACKGROUND/ CONNECTION TO KNOWLEDGE: the students are familiar with number base system

CONTENT:

NUMBER BASE SYSTEM

A number base is the number of digits or combination of digits that a system uses to represent numbers.

When we type some letters or words, the computer translates them in numbers as computers can understand only numbers. A computer can understand positional number system where there are only a few symbols called digits and these symbols represent different values depending on the position they occupy in the number.

A value of each digit in a number can be determined using

The digit
The position of the digit in the number
The base of the number system (where base is defined as the total number of digits available in the number system).

Decimal Number System

The number system that we use in our day-to-day life is the decimal number system. Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represent units, tens, hundreds, thousands and so on.

Each position represents a specific power of the base (10). For example, the decimal number 1234 consists of the digit 4 in the units position, 3 in the tens position, 2 in the hundreds position, and 1 in the thousands position, and its value can be written as

(1×1000)+ (2×100)+ (3×10)+ (4xl)

(1×10³)+ (2×10²)+ (3×10¹)+ (4xl0⁰)

1000 + 200 + 30 + 4

1234

As a computer programmer or an IT professional, you should understand the following number systems which are frequently used in computers.

NUMBER BASE SYSTEM WEEK: 9 JSS 2 Computer ICT

S.N.	Number System and Description
1	Binary Number System Base 2. Digits used : 0, 1
2	Octal Number System Base 8. Digits used : 0 to 7
3	Hexa Decimal Number System Base 16. Digits used : 0 to 9, Letters used : A- F

Binary Number System

Characteristics of binary number system are as follows:

Uses two digits, 0 and 1.
Also called base 2 number system
Each position in a binary number represents a 0 power of the base (2). Example 2⁰
Last position in a binary number represents a x power of the base (2). Example 2^xwhere x represents the last position – 1.

Octal Number System

Characteristics of octal number system are as follows:

Uses eight digits, 0,1,2,3,4,5,6,7.
Also called base 8 number system
Each position in an octal number represents a 0 power of the base (8). Example 8⁰
Last position in an octal number represents a x power of the base (8). Example 8^xwhere x represents the last position – 1.

Hexadecimal Number System

Characteristics of hexadecimal number system are as follows:

Uses 10 digits and 6 letters, 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.
Letters represents numbers starting from 10. A = 10. B = 11, C = 12, D = 13, E = 14, F = 15.
Also called base 16 number system
Each position in a hexadecimal number represents a 0 power of the base (16). Example 16⁰
Last position in a hexadecimal number represents a x power of the base (16). Example 16^xwhere x represents the last position

STRATEGIES AND ACTIVITIES: Activity 1: Teacher revises the previous lesson with the learners.

Activity 2: He introduce the new topic to the learners

Activity 3: He explains the key vocabulary words.

Activity 4: Learners will explain the number base system.

Activity 5: Learners will convert from one base to the other.

Activity 6: Teacher explains in details to bust the learners’ idea about the topic.

ASSESSMENT (EVALUATION): to determine the level of understanding of the topic by the learners, the teacher ask the following questions

Convert the following number from base 10 to binary