From the specification: -

i. Understand the following number bases
i.Decimal
ii.Binary
iii. Hexadecimal
ii. Understand that all computers use binary to represent instructions
iii. Explain why hexadecimal is often used in computer science
iv. Understand how binary can be used to represent whole numbers
v. Understand how hexadecimal can be used to represent whole numbers

Computers are basically a collection of millions of switches. The switches can be on or off represented in binary. Binary is a number system represented by two numerical values:

Place Value

In number systems, a digit’s place value determines how much it contributes to the final total. With decimal numbers (denary), we use base 10, with 10 values (0-9) for each digit

With binary, we use base 2, with 2 values (0 and 1) for each digit

Click the links below for some practice questions

This Power Point cover the basic information related to binary, decimal and hexadecimal conversions.