Program Development: Flowcharts

Lesson objectives

By the end of the week, learners should be able to:

1. Name the main flowchart symbols and state the role of each.
2. Draw a simple flowchart containing a start, process, decision and end.
3. Follow the flowchart by tracing both paths through a decision.
4. Explain why flowcharts help humans review programs.
5. Identify which step represents branching logic.

Key vocabulary

• Flowchart: a diagram showing algorithm steps symbol by symbol.
• Start symbol: the oval at the beginning of a flowchart.
• Process symbol: the rectangle describing a step or action.
• Decision symbol: the diamond asking whether to continue.
• End symbol: the oval marking termination.
• Branch: one of two paths taken by a decision.
• Path: the route through a flowchart following a single choice.
• Trace: predicting results by walking through a diagram.
• Review: examining a process to improve it.

Common misconceptions

• "Every flowchart needs a decision." Simple linear tasks use only start, process and end.
• "Flowcharts replace algorithms." Flowcharts visualise algorithms but do not execute them.
• "Tracing follows only one path." Tracing follows whichever path a decision sends you.

Teacher activities

1. Starter: display two algorithms side by side, one text and one drawn; ask which a developer would prefer reviewing.
2. Name the four main flowchart symbols and demonstrate each with a labelled diagram.
3. Model drawing a simple flowchart with start, process, decision and end.
4. Demonstrate tracing both paths through a decision by hand.
5. Explain why flowcharts help humans review programs.
6. Close with the tracing task and exit question.

Student activities

1. Choose the developer-preferred version from the starter and explain the reason.
2. Name the four main flowchart symbols in their own words.
3. Label a blank start, process, decision and end diagram.
4. Draw a simple flowchart for a basic calculator step.
5. Trace both paths through a decision in the given flowchart.
6. Answer the exit question in one sentence about human review value.

Practical / learning evidence

A labelled start-process-decision-end diagram, a drawn simple flowchart and a traced diagram with both paths recorded. Submit all three for marking.

Resources and preparation

Blank flowchart templates, symbol name cards and sample algorithms. Offline route: paper templates and cards, no device needed. Supervise any physical component demo carefully.

Assessment for learning

Inspect the labelled diagram for all four symbols correctly placed. Check the drawn flowchart for sensible sequencing. Mark the traced diagram for both paths followed. Flag any learner who claims every flowchart needs a decision.

Inclusion and homework

Provide the blank template prelabelled for learners who need scaffolding and allow oral tracing. Extend confident learners with a flowchart containing three decisions and two branches. Homework: convert one sequential algorithm into a flowchart.