Using flow charts to design algorithms

Algorithms are a series of steps and decisions that are completed to solve a problem or carry out an action. Algorithms range in complexity, from relatively simple, such as a recipe, to extremely complex, such as programs that generate flight paths in aviation.

Understanding the series of steps and decisions that comprise algorithms is an important component of Digital Technologies. Being able to generate and interpret algorithms is necessary for students to create digital solutions.

To support students to begin to understand the complexity and sequential aspect of algorithms, teachers can assist students in creating flow charts. The below example is based on the video, 'What are algorithms?', and uses the problem of making a vegemite sandwich.

1. The teacher presents the video, 'What are algorithms?', to the class.
2. The teacher and students co-construct a definition for 'algorithms' from the content presented in the video.
3. The teacher explains that algorithms can be represented as flow charts and that they use standard symbols.
4. The teacher presents a basic flow chart to the class and explicitly teaches the standard symbols used in a flow chart. For example:
SymbolFunction

Oval

Used for the START or END of a flow chart

Parallelogram

Used for INPUTS and OUTPUTS

Rectangle

Used for PROCESSES

Diamond

Used for DECISIONS

Arrows

Show the direction of steps/actions
1. The teacher asks students to re-watch the video, 'What are algorithms?', and create a flow chart to represent the algorithm for making a vegemite sandwich.
• Students may use online tools, such as Grapholite or draw.io to create flowcharts of their algorithms.
2. Students share their flow charts and provide feedback on:
• sequence of steps
• correct use of symbols.
• Students may also test out the created flow charts by performing or acting out the steps to determine if any elements are missing or need revising.
3. Students revise their flow charts in response to feedback.

As students become more familiar with representing algorithms as flow charts, they can be encouraged to represent the series of steps involved in other more complex real-world problems, such as:

• Programming a robotic hand to pick up an object
• Designing and implementing a podcast.

The creation of flow charts can also be used to evaluate digital solutions. As students engage with and explore a digital solution (e.g. navigating a website, such as the interactive map of the Metro Tunnel), they create a flow chart to outline the algorithms that operate behind the interface.

Literacy in Practice Video: Technologies - Using A Flow Chart to Create Codes

In this video, the teacher supports his class to develop a list of instructions and create flowcharts. This video showcases a small section of the lesson that focuses on the terminology students need to understand flowcharts and pseudocodes.

Read the in-depth notes for this video.

Curriculum links for the above strategy: VCDTCD042, VCDTCD043, VCDTCD052.