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Brainlag Learn / GCSE Computer Science

Data representation

Binary, denary and hexadecimal, binary addition and shifts, two's complement, characters, images, sound and compression, with every number generated and checked.

Lessons

  1. Binary, denary and hexadecimalPlace values in base 2 and base 16, converting between the three bases, and units from bits to terabytes. 25 min, free
  2. Binary addition and shiftsAdd binary numbers with carries, recognise overflow, and use left and right shifts to multiply and divide. 20 min, free
  3. Negative numbers in binaryTwo's complement, where the left bit is worth a negative number, and subtraction by adding. Needed for Edexcel 1CP2 and for A-level. 20 min, Plus
  4. Characters and imagesCharacter sets (ASCII and Unicode), how text size is worked out, and bitmap images with resolution, colour depth and file size. 25 min, Plus
  5. Sound and compressionSampling sound, calculating sound file sizes, lossy and lossless compression, run length encoding and Huffman coding. 25 min, Plus

Practise and test

AQA, Pearson Edexcel and OCR are registered trade marks of their owners. Brainlag Learn is independent: it is not affiliated with or endorsed by any exam board, and every question on it is original.