Paper 2 Computational Thinking

Question 1

What is meant by decomposition in computer science and why it is used?

Answer 1

Decomposition involves breaking down a complex problem or system into smaller parts that are more manageable and easier to understand.

Question 2

What is meant by Abstraction in computer science and why it is used?

Answer 2

Abstraction is the process of filtering out the characteristics of problems that are not needed in order to concentrate on those that are needed.

Question 3

What is meant by Algorithms in computer science and why it is used.

Answer 3

An algorithm is a plan, a set of step-by-step instructions to solve a problem.

Question 4

Programmers often use subroutines or functions. Give reasons why programmers use these.

Answer 4

• Subprograms are usually small in size, which means they are easier to write, test and debug than programs.
  They are also easy for someone else to understand.
• Subprograms can be saved separately as modules and used again in other programs. This saves time because the programmer can use code that has already been written, tested and debugged.
• A subprogram may be used repeatedly at various points in the main program. However, the code only has to be written once, resulting in shorter programs.

Question 5

What is the purpose of pseudocode?

Answer 5

Pseudocode is not a programming language, it is a simple way of describing a set of instructions that does not have to use specific syntax.

Question 6

What is the purpose of flowcharts?

Answer 6

A flowchart is a diagram that represents a set of instructions. Flowcharts normally use standard symbols to represent the different types of instructions.