Computer Systems

YEAR 7 ICT

Learning outcomes

• To know the difference between Data and Information

• To understand how Binary code works

• To explain the storage size of Data

Data

“A computer is simple a machine that processes data… so what is DATA?

Starter: Somebody walks up to you with a piece of paper that has 120987 written on it.

In pairs, think of what this could mean (as many as you can!)

Data

BirthdayAmount of money owedPasswordAge of something

*Data only becomes information when you know the context of the data

Data and Information

Complete this activity on Data and Information

Computer Systems

ICT is simple if you understand the three parts of a computer system!

A. Data is entered at the INPUT stage – this is where information is converted into data, e.g. The date 26th September 1995 may be converted to 260995.

The data should be checked or VALIDATED to make sure it’s of the correct type. Then it should be VERIFIED or be correct.

INPUT OUTPUTPROCESS

Computer Systems

B. The computer then PROCESSES the data – processing involves turning the input data into something else, e.g. Exam results being put into a computer which calculates the average score

C. The results are shown at the OUTPUT stage – Output is when the computer communicates the results of the processing.

The most common ways of doing this are a screen display and print out.

At this point the data becomes INFORMATION again!

GIGO

Computers are machines that process data. They’re stupid and don’t understand the data they process!

If you get a computer to process data that’s incorrect, the results will be meaningless!

This is called Garbage In, Garbage Out (GIGO)

e.g. If you program a computer to work out the total cost of buying 3 pizzas at £1.99 each, but you type in £1.9 by mistake, you’ll get the wrong answer

INPUT OUTPUTPROCESS

Data is stored in Bytes

• Computers run on electricity – they’re made up of circuits which can either be ON or OFF

• Computers use a Binary code to represent data. A circuit that is switched ON represents 1 and a circuit that is switched OFF represents 0.

The word “ICT” in binary code = 01001001 01000011 01010100

I C T

Activity

• Go to this website which converts words to binary code and binary code to words

• Decode the following messages in binary code. Click here to start!

Whole Class Activity

Decide as a class if the sentences below are true or false

1. Computers are machines that process data

2. Computers are clever; they understand the data they process

3. If you get a computer to process data that is incorrect, the results will be meaningless

4. GIGO stands for Grab It, Get Out

5. Data is information that has no meaning without a context

Bits, Bytes, and Megabytes

1 Bit = Binary Digit

8 Bits is 1 Byte

1 Kilobyte is a thousand bytes

1 Megabyte is a million bytes

1 Gigabyte is a thousandmillion bytes

0 or 1

01000011 - the letter ‘C’

60kb - The size of a small image taken

5Mb - The size of an average music file (MP3)

6Gb - The size of an average DVD movie

c

Paired Activity

In pairs discuss the following questions and then feedback your answers to the class.

Asif wishes to back-up some important computer data. His computer copies files at a speed of 1 million bytes per second.

How long in seconds will it take to copy each of the following:

• One letter (20Kb)• One hundred tunes (5Gb in total)• Thirty digital pictures (1Mb in total)

Plenary

Complete the wordsearch on today’s lesson!You have to find:

Binary Byte Code Data

GIGO

Information

Input

Output

Process

Homework

Complete the questions on today’s lesson!