1. BTEC NCF Dip in Comp: Unit 01 Principles of Computer Science Lesson 01 – Computational Thinking
Mr C Johnston

2. Learning Outcome
Understand the term and processes in computational thinking.
Be able to use the skills of:
Abstraction
Decomposition
Algorithmic thinking

3. Question….. What is computational thinking? Computational thinking:
The use of computers to solve problems.
Development of algorithms to solve problems.
Using abstraction, decomposition and algorithmic thinking

4. Computational thinking skills Representation of problem elements
Decomposition
Computational thinking skills
Representation of problem elements
Pattern Recognition
Pattern generalisation and abstraction

5. Activity
Text Book
Article #1
Create detailed notes on each of the main computational thinking techniques

6. Revision…. Decomposition Abstraction Algorithmic Thinking
Pattern Recognition #1
Abstraction #1 | #2
Decomposition
Breaking down a large problem into smaller sub-problems. Smaller problems are easier to solve. Will often be instructions or questions
They can be created independent of the other problems.
They can be tested independently.
Then combined to produce the full problem.
There is not always one right answer. A problem could decomposed in several valid ways.
Abstraction
Representing 'real world' problems in a computer using variables and symbols and removing unnecessary elements from the problem.
Algorithmic Thinking
Identifying the steps involved in solving a problem – need to know required Inputs / Processes / Storage / Outputs

7. Activity – Decomposition Practice
Imagine you have to design a menu for a takeaway. How would you decompose this complex problem in an attempt to solve it? Draw a diagram to show the decomposition.
Imagine a crime has been committed. How would you decompose this complex problem in an attempt to solve it? Draw a diagram to show the decomposition.
Imagine you have a website to create. How would you decompose this complex problem in an attempt to solve it? Draw a diagram to show the decomposition.
Example recipe decomposition

8. Activity – Abstraction Practice
For the map below, identify how abstraction would be used to represent the map in a computer.
Describe how this map would be represented by a computer, consider the variables and objects that would be used, and the elements that would be ignored.
Redraw the map as an abstract solution
Think about a second scenario where a real life problem, or object, would need to be developed into a computer model. How would abstraction be used to represent this problem, or object, in a computer?

9. Activity
You have been asked to create to clone of Space Invaders for a new games console. Using the process of reverse-engineering depose the problem
You must identify the distinct steps of the problem
Expand you analysis of the game (eg identify patterns and common elements or features).
Introduce some programming terms to identify variables in the example game

10. Algorithm Design
Algorithms #1 | #2
An algorithm is simply a set of instructions that are followed to solve a part of a problem
Programs are made from a number of different algorithms
Core part of algorithm design is the description of the main processes, the required inputs, desired outputs, any storage required
A quad diagram can be used to illustrate the requirements
Input Required
Processes Required
Output Required
Storage Required

11. Algorithm Design Process
Step #1: Understand the problem
Make sure that you fully understand the problem you have been asked to solve
Step #2: Identify the inputs
What values will be input by the user?
What type of data will this be?
Step #3: Identify the processes
What kind of calculations are involved?
Are there any special values we need to know?
Step #4: Identify the data storage
Think about storing data – what would be need next time the solution is run?
If this is needed what type of data will be stored?
Step #5: Identify the data storage
What information must be output?
In what format must the output be shown?
Step #6: Collate your notes in a quad diagram

12. Activity – Algorithm Design
Analyse these problems and draw a quad diagram to show a solution
A system which converts metric weights to imperial
Finding the highest value in a list of numbers
If a word is a palindrome or not
A website logon system requiring preregistered users to enter their user name and password to access content
A system produces quotes for painting a room. It takes the measurements of a rectangular room, the price per SQM of the paint and the labour charge to calculate the quote.

13. Review