Organising Data And Structure

Question 1

The nature of data

Answer 1

Data is made up of raw facts and figures and can be represented in many different forms including text, numbers, pictures, sounds and video clips. Information can be derived from data when it is processed.

Question 2

Representation of numbers

Answer 2

You will need to be familiar with three different counting systems. These are denary, binary and hexadecimal.

Question 3

Deanery

Answer 3

The first counting system that you need to be familiar with is the denary counting system, also known as the Base 10 or decimal counting system. In the denary counting system, the digits 010, 110, 210, 310, 410, 510, 610, 710, 810, 910 are used to represent numbers. The number 13810 for example, actually means 1 ‘hundred’, 3 ‘tens’ and 8 ‘units’. This gives the total one hundred and thirty-eight:

Question 4

Binary

Answer 4

The second counting system that you need to be familiar with is the binary counting system, also known as the Base 2 counting system. In order for data to be processed by a computer system, it must be converted into binary format. This is because computer systems can only store and process Binary digITs, also known as BITs. A BIT is either a 12 or 02. You may think of this as a light switch, where the switch is either ON or OFF:
 If the switch is ON it is stored as the digit 1.
 If the switch is OFF it is stored as the digit 0.
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A binary number is a string of BITs, for example 100010102:
The binary number 100010102 is therefore a binary representation of the denary number 13810 (12810 + 810 + 210).

Question 5

Hexadecimal

Answer 5

The third counting system that you need to be familiar with is the hexadecimal counting system, also known as the Base 16 counting system. In the hexadecimal counting system, the digits 016, 116, 216, 316, 416, 516, 616, 716, 816, 916 are used to represent 1–9 and then the characters A16, B16, C16, D16, E16 and F16 are used to represent 10–15. The hexadecimal number 8A16 for example:
The hexadecimal number 8A16 therefore represents 8 ‘sixteens’ and 10 ‘units’. This gives the total one hundred and thirty-eight. Remember that A16 = 1010, B16 = 1110, C16 = 1210, D16 = 1310, E16 = 1410, F16 = 1510.
The hexadecimal system is widely used as binary numbers can be quickly converted into hexadecimal numbers that are more convenient for humans to use. For example, a telephone conversation where you might read out the binary number
100010102 could cause confusion. It’s easier to say 8A16, and mistakes are less likely to be made.