DGB 1: Algorithms
An algorithm is a clear sequence of instructions for solving a task or reaching a result. Everyday instructions can be used to understand why order, completeness and precision are essential when computers are expected to carry out instructions.
Curriculum reference
[Bearbeiten]| Area | Classification |
|---|---|
| Competence area | Production |
| Focus | Following, executing and independently formulating instructions (algorithms) |
| Competence | Understand, execute, test and formulate clear step-by-step instructions. |
Learning objectives
[Bearbeiten]Students can:
- explain the concept of an algorithm in simple terms;
- follow a sequence of instructions accurately;
- recognise that the order of steps can affect the result;
- identify ambiguous, incomplete or unnecessary instructions;
- formulate clear step-by-step instructions themselves;
- test an instruction sequence and improve errors;
- recognise algorithms in everyday situations;
- represent simple processes as numbered lists or flow diagrams;
- explain why computers require precise instructions.
Learning content
[Bearbeiten]What is an algorithm?
[Bearbeiten]An algorithm is a finite, ordered and sufficiently clear sequence of steps used to solve a problem or complete a task. Examples from everyday life include recipes, route instructions, assembly instructions or rules for sorting objects.
Clear and complete instructions
[Bearbeiten]Instructions must contain the information required by the person or system carrying them out. “Put it there” is unclear if “it” and “there” have not been defined. Precise instructions describe the action and the object or condition involved.
The order matters
[Bearbeiten]For many processes, changing the order leads to a different or incorrect result. Instructions for making a jam sandwich, for example, cannot sensibly begin with “spread the jam on the bread” if the bread has not yet been prepared.
Ordering steps is therefore a fundamental form of algorithmic thinking.
Execute and test
[Bearbeiten]An algorithm can be checked by following it exactly. If a person has to guess or add missing information, the instructions are not yet clear enough. Testing helps reveal these weaknesses.
Finding and correcting errors
[Bearbeiten]Improving an incorrect or unclear sequence is a simple form of debugging. The problem is identified, one step is corrected and the sequence is tested again.
Ways to represent algorithms
[Bearbeiten]Simple algorithms can be written as numbered instructions, represented using symbols and arrows or shown in a basic flow diagram. The representation should make the order easy to understand.
From everyday instructions to computers
[Bearbeiten]Computers execute instructions according to defined rules. They do not automatically fill in missing intentions like people often do. This is why precise descriptions are especially important in programming.
Classroom activities
[Bearbeiten]Robot instructions
[Bearbeiten]One student acts as a “robot” and follows instructions literally.
Task: Write instructions for a simple classroom action. Test them without adding unstated assumptions and improve unclear steps.
Put the steps in order
[Bearbeiten]A familiar activity is presented as mixed-up individual steps.
Task: Put the steps in the correct order and add a missing step if necessary.
Expected outcome: A logically ordered and complete process.
Improve ambiguous instructions
[Bearbeiten]Task: Rewrite vague instructions so that another person can carry them out without asking additional questions.
Design your own algorithm
[Bearbeiten]Task: Choose a simple problem and write a numbered algorithm. Ask another student to test it exactly as written and revise it based on the test.
Self-check
[Bearbeiten]- I can explain what an algorithm is.
- I can follow instructions in the correct order.
- I can identify unclear or missing steps.
- I can test and improve an algorithm.
- I understand why computers need precise instructions.