Lesson Notes By Weeks and Term - Primary 3

Components of the computer system unit I&II

WEEK 4&5


TERM: 3rd


TOPIC: Components of the computer system unit 1&11

Subbtitle: Hard disk

Learning Objectives

At the end of this this lesson, pupils should be able to:

  1. Identify the hard disk drive
  2. Differentiate between the hard disk drive and floppy disk
  3. State the use of hard drive

Resources and materials:

Scheme of work

Online information

Instructional material:



Pictures/charts of disk drive and the types of disk drive

Building Background/connection to prior knowledge: pupils are familiar with the topic in their previous classes.



A hard disk drive (HDD) is a non-volatile computer storage device containing magnetic disks or platters rotating at high speeds. It is a secondary storage device used to store data permanently, random access memory (RAM) being the primary memory device.




  1. A floppy disk is a circular piece of mylar or other plastic like material coated with iron oxide. The hard disk is a stack of few thin metal plates, usually coated, usually coated on both side with magnetized material.
  2. Data is recorded in the form of magnetic dots on spots on tracks in floppy disk . Data is stored as magnetic spots on tracks that concentric circles on the surface of disks in Hard disk.
  3. The flexible disk is housed in a plastic jacket I the floppy disk. The flexible disks is housed in a metal jacket in an hard disk.
  4. Hard disk are often called a fixed disk.
  5. Floppy disk holds less data that is 1.1.4 MB. Hard disks holds more data that is several GBs


The hard disk is used to store the operating system and programs required to keep your computer running. Basically hard disk is a magnetic type storage media which, when required reads the specific portion of memory and provides it for processing. Its a kind of permanent storage for your work, you can't store any data on the RAM as it erased each time you turn off the computer. And as per the memory hierarchy the more faster storage you need gets more pricier. So at the time of any program execution the data from the hard disk is loaded onto memory for execution and hard disk can can provide virtually more memory for storing various programs and data.

Also the media files get stored on the hard disk.

Hard disk is used to store your information on a secondary storage.

1- hard disk save your data for a very long time

2- hard disk is not volatile

3- hard disk is very cheap compared to “RAM and Chace”

Strategies& Activities:

Step :Teacher revises the previous topic.

Step 2:Teacher introduces the new topic.

Step3:Teacher explains the new topic.

Step4: Teacher welcomes pupils questions.

Step5: Teacher evaluates the pupils.

Assessment & Evaluation:

  1. Identify the hard disk drive
  2. Differentiate between the hard disk drive and floppy disk
  3. State the use of hard drive

WRAP UP(CONCLUSION) Teacher goes over the topic once again for better understanding.

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