That Blue Square Thing

Computer Science GCSE

Note: this page deals with the old Edexcel GCSE (grades A-G) which no longer exists. I'm keeping it as an archive and because a number of the resources will still apply to newer (grades 1-9) courses. The AQA GCSE CompSci pages deal with a current course.

Bytes, bits and transfer speeds

Binary numbers are made up of bits, of course. We usually deal with 8-bit binary numbers when we're converting. But you need to understand and know how to use bigger numbers as well.

An 8-bit binary number is a Byte. Bytes can be built up to form KiloBytes, MegaBytes, GigaBytes and TeraBytes - the units we usually use when we're describing the sizes of files or the storage space on a hard drive or some form of secondary storage device.

You need to be able to work with these measurements and apply them to file sizes and file transfer rates.

PDF iconBytes and how they work - the key points and terminology you need to know

PDF iconFiles sizes and File transfer speeds - how to calculate file size and file transfer speeds

Revision exercises

Questions about file size and file transfer speed are most likely. Again, there won't be many marks on this sort of thing, but it's important to try and pick up as many of the simple marks as possible.

PDF iconFile size and transfer speed exercises - questions to try

PDF iconAnswers