507·Computer Science · GCSE
Everything
Is a Number
GCSE Computer Science Knowledge Mat — Data (PDF)
A photograph, a song and the word 'hello' sit on the same disc — what do they have in common? The five data types the DfE names and why choosing one is a decision, with a figure that draws a one-dimensional array beside a two-dimensional one and puts the index under the box, never in it. Then binary and hexadecimal as one number written twice, with a place-value strip that sums its own bits to 106 and splits itself into the nibbles 6 and A. Then text, sound and graphics, with a bitmap small enough to count: the grid is the file, and the file size is multiplied out of the grid's own dimensions. Three capacity formulae, a worked file-size calculation that ends by naming which convention it counted in, sixteen terms, and the misconceptions that cost marks.
Everything else this site has for Computer Science: Computer Science teaching resources
One purchase covers the school that buys it. Print it, copy it, hand it round your department. Not for passing to other schools or uploading anywhere.

One landscape A4 page on one part of the GCSE Computer Science course, anchored to the DfE's own subject content and Ofqual's subject level conditions rather than a board's paraphrase — so it holds whichever specification a department follows. It carries data types and data structures, binary and hexadecimal conversion, binary addition and shifts, the representation of text, sound and graphics, and the calculation of data capacity — then the vocabulary, a worked file size, and the misconceptions that cost marks.
Whether overflow is examined differs between specifications, and the sheet says so rather than teaching it as common ground. Nothing is reproduced from a past paper, a textbook or a specification, and every figure is drawn in code, so nothing on the sheet is licensed from anybody.
Sold by subject: all four Computer Science sheets for one price. A knowledge organiser stores a unit and is revised from afterwards; this is meant to be on the table while the lesson is happening.
- Written to
- The DfE GCSE subject content for computer science (updated 31 March 2025) and Ofqual's subject level conditions for qualifications examined from 2022 onwards (Ofqual/19/6472), quoted; no board's specification, mark scheme or past paper. Every number printed is computed by the figure that prints it
- Intended for
- computer science teachers — on the desk during the lesson, not a student revision guide
- Extent
- 1 page · 8 sections
—·Look inside
Real pages, straight from the PDF
Click any page to see it full size.
—·Contents
All 8 sections
Taken from the booklet’s own contents page, so the page numbers are the real ones.