Describe how a check digit is used to detect errors in data entry and identify examples of when a check digit is used, including international standard book numbers (ISBN) and bar codes

Including identifying each stage and performing these tasks for each stage: analysis: abstraction, decomposition of the problem, identification of the problem and requirements; design: decomposition, structure diagrams, flowcharts, pseudocode; coding: writing program code and iterative testing; testing: testing program code with the use of test data. Including: inputs, processes, outputs, storage. Including: structure diagrams, flowcharts, pseudocode. Including: stating the purpose of an algorithm, describing the processes involved in an algorithm. Limited to: linear search, bubble sort, totalling, counting, finding maximum, minimum and average values. Including: range check, length check, type check, presence check, format check, check digit. Including: visual check, double entry check. Limited to: normal, abnormal, extreme, boundary. Extreme data is the largest/smallest acceptable value. Boundary data is the largest/smallest acceptable value and the corresponding smallest/largest rejected value. Including, at each step in an algorithm: variables, outputs, user prompts. Precision is required when writing algorithms, e.g., x > y is acceptable but x is greater than y is not acceptable.