Computing
Computer Science LearnITWithMrC ⛯ Year 7 Year 8 Year 9 GCSE

Lesson Video 1

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What do I need to Learn?

 I need to learn how to understand and explain the term algorithm.

Key Terms

Algorithm Sequence Algorithmic thinking

An Algorithm is Like a Recipe

An algorithm is simply a sequence of steps used to solve a problem, like a recipe. See right. Our recipe might tell us how to create an apple pie or lemon cake.

To get a computer to do something we have to tell it what to do. We do this by using a set of instructions. These instructions are called algorithms.

An algorithm has a defined outcome – a defined end. Algorithms can be written in many different ways. Each way has a different cost, different speed and requires different external hardware.

Algorithms in programming

You are creating an algorithm every time you write a program. You are creating a set of steps to perform a task. Before we create a computer program we write it out in one of two ways.

1. As a set of intructions like a recipe.

2. As a flowchart.

Creating an algorithm

The following pseudocode algorithm has an error. The program is suppose to ask the user for the length and width of a rectangular room, and then display the room's area. the program must multiply the width by the length in order to deteremine the area.

```area= width x length.
display "what is the room's width?".
input width.
display "what is the room's length?".
input length.
display area.
```