A self-marking Stretch (HPA) worksheet for OCR GCSE Computer Science J277 1.2.4: how characters, images and sound are stored in binary. Students answer on screen and press Check to get instant feedback. Every attempt is recorded, so you can see who got it right first time and who needed several tries. What’s included • Stretch (HPA) worksheet: 25 questions • Teacher answer key with full working for both the Stretch and the free Support worksheet (printable PDF) Topics covered • Characters: encoding and decoding letters (including lower case), ASCII vs Unicode, the minimum number of bits needed, and the impact of switching character sets • Images: decoding a 2-bit colour image, colour depth, resolution, metadata, and file sizes in bits and bytes • Sound: sample rate, bit depth, duration, file size and duration calculations, and the quality vs size trade-off Features • Hands-on tasks: type characters into 8-bit binary place-value boxes and click pixels to draw an image from binary • Correct answers lock, and every changed answer counts as a new attempt • Students download a results file showing their score, attempts per question and right-first-time results, plus a completion code to upload to Google Classroom or Teams • Works offline in any browser on PC, tablet or phone, with no logins or installs Pairs with the free Support (LPA) worksheet on the same topic for a fully differentiated lesson. Search “FREE OCR GCSE J277 Characters, Images & Sound”. Designed for practice and homework, not formal assessment.

A free, self-marking worksheet for OCR GCSE Computer Science J277 1.2.4 (23 questions). Students turn characters into 8-bit binary, colour in a pixel image from binary and calculate image and sound file sizes. They press Check to get instant feedback, and correct answers lock. Every attempt is recorded. Students download a results file showing their score, how many tries each question took and what they got right first time, ready to upload to Google Classroom or Teams. No logins, works offline, and runs in any browser on a PC, tablet or phone. If you find it useful, a quick review helps other teachers find it.