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Introduction to algorithms lesson plan


What is an algorithm?

An algorithm is a set of step-by-step instructions used to solve a problem. They are used by both human beings and computers.

Algorithms for Humans

Common examples of algorithms for humans include:

Fire evacuation Procuedures

Fire evacuation Procedures

Cooking Recipes

Cooking Recipes

Furniture assembly instructions

Furniture assembly instructions

Washing Machine Usage Instrucitons

Washing Machine Usage Instrucitons

Computer Algorithms

Algorithms for Computers

Computers require algorithms to function and these usually come in the form of software. Computers differ from humans in that the instructions provided must completely unambiguous – they must be clear and not open to interpretation.

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Computer Algorithms used in computers are usually written in text or block based programming languages such as Python or Scratch, though some algorithms are physically wired into a computer.


Video – What is an algorithm?


Activity 1

Write an Algorithm Activity

Choose one of the the following and write an algorithm for it:

  • How to make your favourite food
  • Your favourite viral Tik-tok dance
  • How to make a paper plane
  • How to make a cup of tea for a room full of people
  • Drawing a picture of a house

Activity 2

Activity 2 – Alien shopping algorithm

An alien has landed on earth and you have decided to send him on an important mission – to do your weekly shopping down at the supermarket! You have been given a shopping list. The alien has never been shopping before – can you write a set of instructions for it to do the shopping for you?


Your algorithm must be:

  • Step-by-step.
  • Unambiguous – Each step must be completely clear and specific.