Flowcharts and pseudocode

An algorithm can be shown two ways. A flowchart draws it with standard symbols joined by arrows. Pseudocode writes it in short, structured English, such as Read price. Both use the same building blocks: input, processing, output, decisions and loops. Paper 1 asks which structure IF ... THEN ... ELSE belongs to: selection.

By the end of this page you can

• Name the flowchart symbols and what goes in each
• Use operators, including MOD and DIV
• Tell sequence, selection and loops apart
• Put an algorithm’s statements in order
• Write a short algorithm in pseudocode

Goals tick themselves off as you try the activities below.

Photo: Spideog, CC BY-SA 4.0, via Wikimedia Commons. Maker’s logo and part number blurred, resized, JPEG q74.

Programmers once drew flowcharts with templates like this: each shape has one job.