1. Algorithms
Y10 Introduction

2. WHAT IS AN ALGORITHM?
It is a set of instructions of how to carry out a process. An algorithm lists the steps that must be followed to complete the process and to reach the solution

3. Examples of algorithms:
A knitting pattern
A set of instructions telling you how to put a kit together (eg. an IKEA kitchen unit)
A recipe in a cook book
An algorithm can be represented diagrammatically in the form of a flow chart.

4. A flow chart
A flowchart consists of a sequence of instructions linked together by arrows to show the order in which the instructions must be carried out.
It provides detailed steps.
Each instruction is put into a box. The boxes are different shapes depending upon what the instruction is.

5. Process shapes… Remember not to create the flow chart in WORD…
Instead do this in POWER POINT and change
File – Page Layout to PORTRAIT
Autoshapes has the shapes you need to use
Input or output
START / END
Query / question
Human process
i.e. you doing
something! No
Yes
Printed output
Save to file

6. More shapes You can also use the following shapes: Predefined process
Used for a sequence of instructions which is defined somewhere else (eg. in a subroutine)
Connector
– to link with a different page or another part of the program
(Note: all these shapes can be found under ‘AutoShapes’
if you click the Drawing icon on your tool bar)
Predefined process

7. TASK 1 MAKING A CUP OF TEA!
The following list represents the steps needed in order to make a cup of tea. Put the list in the right order and produce an algorithm in POWERPOINT showing the processes and decisions you need to make.
Take tea bag out of cup
Boil the water
Put tea bag in cup
Add milk?
Pour boiling water in cup
Fill kettle
Stir
Ready
Add sugar ?
Fetch cup
Answers follow

8. Pour boiling water in cup
The answers…
START
Fill kettle
Fill kettle
Boil the water
Fetch cup
Put tea bag in cup
Pour boiling water in cup
Take tea bag out of cup
Add sugar ?
Stir
Add milk?
Ready
Boil the water
Fetch cup
Put tea bag in cup
Pour boiling water in cup
Take tea bag out of cup
Add sugar ? N
Stir in sugar
Add milk? N
Now add the shapes…
Pour in milk
Ready

9. Skills in Powerpoint to create your algorithm….
To change
this to ….
To tidy up the whole column…
select all (drag around all shapes)
Go to DRAW
Select ALIGN or DISTRIBUTE

10. mess up the side sections…! Boil the water
START
Fill kettle
To this…
but take care as it can
mess up the side sections…!
Boil the water
Fetch cup
Put tea bag in cup
Pour boiling water in cup
Take tea bag out of cup
Add sugar ? N
Stir in sugar
Add milk? N
Ready
Pour in milk

11. TASK 2 A PREDEFINED PROCESS
In order to carry out no. 8 in the list above, you will need to instruct the user how to fill a kettle.
(a) Produce a set of instructions called ‘Filling a kettle’ and then
(b) update your algorithm for task 1 to include this predefined process.

12. TASK 3 MAKING A CUP OF COFFEE!
How would your algorithm change for making a cup of coffee instead of tea? Amend your algorithm in Task 2 (b) in order to produce a new diagram.

13. Now try to create one on a PC
This should always be done in POWERPOINT…..
NEVER, EVER, EVER in WORD!