Chapter 1 Data representation: Unit 1.1: Number systems

Question 1

Define denary number system

Answer 1

Number system that counts in multiples of 10 (10s, 100s, 1000s)

Question 2

Define binary number system

Answer 2

Base 2 number system i.e based on the number 2
Only has 2 values: 0 and 1

Question 3

Describe the method for converting binary to denary.

Answer 3

Each time a 1-value appears in a binary number column, the column value (heading) is added to a total.

Question 4

Define hexadecimal number system

Answer 4

Base 16 number system

Question 5

What does A, B, C, D, E and F mean in denary?

Answer 5

A=10
B=11
C=12
D=13
E=14
F=15

Question 6

Describe the method for converting hexadecimal to binary.

Answer 6

Starting from the right moving to the left, split the binary number into groups of 4 bits.
If the last group has less than 4 bits, then simple fill in with 0s from the left.
Take each group of 4 bits and convert it into the equivalent hexadecimal digit.

Question 7

Describe the method for converting hexadecimal to denary.

Answer 7

Involves the numbers 4096, 256, 16, 1.

Take each of the hexadecimal digits and multiply it by the heading values.
Add all the resultant totals together to give the denary number.

Question 8

Name 4 uses of the hexadecimal system.

Answer 8

Error codes
MAC (Media Access Control) Addresses
IPv6 (Internet Protocol) Adresses
HTML (Hypertext Mark-up Language) Colour Codes