Lesson

Do you remember what an iteration is? Try this question.

Follow the algorithm below to fill in the results.

Step | Instruction | Result |
---|---|---|

1 | \text{Start with the number $29$} | ⬚ |

2 | \text{Subtract $1$ from this number} | ⬚ |

3 | \text{Repeat step $2$ three more times} | ⬚\\⬚\\⬚ |

4 | \text{Double the number} | ⬚ |

Worked Solution

Idea summary

Iteration means to repeat steps in an algorithm.

This video shows us how to set up and follow a flow chart.

What is the output of this algorithm if the input is 4?

Worked Solution

Idea summary

A linear sequence is a flow chart that moves from beginning to end in one straight line. There are no decisions, just a some steps to do.

We can show all our special coding things in a flow chart. This video shows us branches, loops and some special functions like print and set.

What is the output of this algorithm if the input is A=2 and B=5?

Worked Solution

Idea summary

On a flow chart:

Branch is shown by two arrows coming out of a decision box.

Iteration is shown as a path that loops back to itself.

Print can be used to display an output.