Algorithms as Recipes: Applied Scenario

≈ 24 min

Applied Scenario

Apply the idea in context while keeping the assumptions, units, safety and affected people visible.

This extension applies that lens specifically to Algorithms as Recipes.

What is an algorithm?

An algorithm is a set of clear, step-by-step instructions that solve a problem or finish a task. You already follow algorithms every day. A recipe for making tea is an algorithm. So are the directions to a friend's house.

A good algorithm has three qualities:

Ordered - the steps happen in the right sequence.
Clear - each step says exactly one thing to do.
Complete - no important step is missing.

Here is an algorithm for making a cup of tea:

Boil the water.
Put a teabag in the cup.
Pour the hot water into the cup.
Wait 2 minutes.
Take out the teabag.

Order matters. If you pour the water before the teabag is in the cup, you get plain hot water, not tea.

Why coders love algorithms

Before writing any code, a coder first writes the algorithm in plain words. This is called planning. Planning in words is faster than fixing broken code later.

Example: an algorithm to check the weather before school:

Look outside.
If it is raining, take a raincoat.
If it is sunny, take a hat.
Leave for school.

Digital Foundations: Coding & Data — Applied Scenario: Which of these is the best algorithm for washing your hands? Look carefully at the order of the steps.

Dry hands, wet hands, add soap, rub, rinse

Wet hands, add soap, rub hands, rinse, dry hands

Add soap, dry hands, rinse, wet hands, rub

Rinse, dry hands, add soap, wet hands, rub

Digital Foundations: Coding & Data — Applied Scenario: What single word do coders use for a clear set of step-by-step instructions that solves a problem?

Digital Foundations: Coding & Data — Applied Scenario: During load-shedding a learner writes a checklist algorithm to save phone battery before the power goes off:

Charge the phone fully.
Turn on power-saving mode.
Close apps you are not using.

Which step is in the wrong place for this to work well?

Step 1 (Charge the phone fully) should come first - it is already correct

Step 1 (Charge the phone fully) should come last, after saving mode

Step 2 (Turn on power-saving mode) should come first, before charging

No step is out of order; the algorithm is fine as written

Name the original topic being extended by this applied scenario lesson.

Which statement is the best evidence-led starting point for Algorithms as Recipes: Applied Scenario?

What is an algorithm? An algorithm is a set of clear, step-by-step instructions that solve a problem or finish a task. You already follow algorithms every day. A recipe for making tea is an algorithm. So are the directions to a friend's house. A good algorithm has three qualities: 1. Ordered - the steps happen in the right sequence. 2. **Clear

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Spreadsheets and Trusting Online Information

A conclusion needs no observations, calculations or stated assumptions.