Other Standard Methods of a Solution (Cambridge International IGCSE Computer Science)

Totalling & Counting

Spec point — 6.3.4a · 6 Understand standard methods of solution

What is totalling?

• Totalling is keeping a running total of values entered into the algorithm
• An example may be totalling a receipt for purchases made at a shop
• In the example below, the total starts at 0 and adds up the user inputted value for each item in the list

What is counting?

• Counting is when a count is incremented or decremented by a fixed value, usually 1, each time it iterates
• Counting keeps track of the number of times an action has been performed
• Many algorithms use counting, including the linear search to track which element is currently being considered
• In the example below, the count is incremented and each pass number is output until fifty outputs have been produced

• In the example below, the count is decremented from fifty until the count reaches zero. An output is produced for each pass

Maximum, Minimum & Average

Spec point — 6.3.4a · 7 Understand standard methods of solution

• Finding the largest (max), smallest (min) and average (mean) values in a list are frequently used method in algorithms

• Examples could include:

  • Calculating the maximum and minimum student grades or scores in a game
  • Calculating the average grade of students in a class test

• In the example below, in a list of student test scores, the highest, lowest and average scores are calculated and displayed to the screen