The document discusses how computers represent data using binary numbers (1s and 0s). It explains that binary is used because it provides an easy way to represent two states (on/off) in storage devices. It then discusses how different numbers of bits (binary digits) can be used to represent different numbers in binary, and provides examples of converting between binary and decimal numbers. Finally, it briefly introduces the concept of data compression for reducing the size of files.

1. Data Representation Represent! How information is stored in a Computer System With our resident Binary enthusiast … Brian Sup Homies! only 10 people understand binary Mr McAlpine Hamilton Grammar School

19. Data Representation How text is represented/sent in a computer system ASCII Code UNICODE Memory Sizes Im the greatest Dancer!

30. Data Representation Graphics How are Graphics stored in a Computer System Calculating memory requirements These glasses are X-Ray

36. Backing Storage Requirements This image of screech measures 2 inches by 2 inches. It has a resolution of 80 dpi using 256 colours Memory Required Total Pixels (2 * 80) * (2 * 80) = 25, 600 Each pixel could be one of 256 different colours 256 requires 8 bits 25,600 * 8 = 204, 800 bits 204, 800 = 25,600 bytes or 25 kilobytes

37. Your Turn This idiots picture measures 3 inches by 2 inches It has a resolution of 150 dots per inch. It uses TRUE COLOUR which uses 24 bits per pixel 395.5 Kilobytes Worksheet 4

38. Data Representation The need for Compression Different methods of Compression Compress Yourself!