2022 Tasks
1 - Data Representation
2 - Data Transmission
3 - Hardware
4 - Software
5 - The Internet & Its Uses
6 - Automated and emerging technologies
7 - Algorithms
1 of 2

1.1 Number Systems

Binary is the foundation of computer science and is an excellent place to start your Computer Science studies. If you have covered binary numbers at KS3 or in previous courses, you may find that you move through this topic quicker than others.

Keep an eye out for the tables in each lesson which show what you are expected to know for the CIE iGCSE Computer Science exam as this may be different from other exam boards.

TopicI should be able to…
1.1Understand how and why computers use binary to represent all forms of data
Understand the denary, binary and hexadecimal number systems
Convert between
(i) positive denary and positive binary
(ii) positive denary and positive hexadecimal
(iii) positive hexadecimal and positive binary
Understand how and why hexadecimal is used as a beneficial method of data representation
Add two positive 8-bit binary integers
New for 2023Understand the concept of overflow and why it occurs in binary addition
New for 2023Perform a logical binary shift on a positive 8-bit binary integer and understand the effect this has on the positive binary integer
New for 2023Use two’s complement to represent positive and negative 8-bit binary integers