Lesson

Do you know how to use a function machine? It's like an algorithm with just one step.

Look at the following function machine:

Complete this table of inputs and outputs:

Input | Output |
---|---|

6 | |

7 | |

8 |

Worked Solution

Idea summary

Function machines show the

**relationship**between the**input**(starting number) and**output**(answer).If you are given the output, you can find the input by

**reversing**the rule.

To explore what an algorithm is, we'll use an example of getting dressed, then see how we can use an algorithm to sort some coins into order by value.

Write 327 in expanded form by following these steps:

a

First, write down the hundreds part.

Worked Solution

b

Next, write down the tens part.

Worked Solution

c

Now, write down the units (ones) part.

Worked Solution

d

Now, write the number in expanded form by adding these three numbers together.

⬚+⬚+⬚

Worked Solution

Idea summary

An **algorithm** is a set of steps that tells us what we need to do, and when. It can be used in lots of ways, but we have seen how to use it to sort numbers into different orders.