The card on the help desk wall
On the help desk wall is a card: "Cannot print? Do these steps." A student on their first day follows it and fixes a jam.
Nobody had to explain it. The steps are clear, in order and they always end. Steps like these make an algorithm (a set of clear steps in order).
By the end of this lesson
Note
I can write an algorithm as a flowchart (a picture of steps) and as a written description.
Key words
| Word | What it means |
|---|---|
| Algorithm | A set of clear steps, in order, that solves a problem |
| Flowchart | A picture of an algorithm made of shapes and arrows |
| Terminator | The oval shape that starts or ends a flowchart |
| Decision | A diamond that asks a yes or no question |
| Sub-process | A box that stands for a whole set of steps drawn elsewhere |
| Written description | An algorithm in words, with numbered steps |
| Hierarchical marker | A number such as 1.1 that shows a step inside another |
The cells students fill in are left blank in this preview.
Starter
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3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
An algorithm has clear, ordered steps
An algorithm is a set of steps that solves a problem. Its purpose is to let anyone, or any computer, get the same result.
A good algorithm has four characteristics. Each step is clear. The steps are in the right order. It ends after a set number of steps. It gives an output.
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3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.