Computational Thinking

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1 Objectives

Developing Algorithms learning strand, specifically:

  • be able to understand and articulate a given problem
  • be able to develop algorithms for given problems
  • understand that algorithms are implemented on digital devices as programs.
  • design simple algorithms using loops (repetition), and selection (if statement)

2 Computational Thinking

Learn It

  • Lets recap:
    • Computational thinking is the thought processes of understanding a problem and presenting its solution(s) in such a way that a computer or human can understand and a computer can effectively carry out.
  • Lets break down the concept above:
    1. understanding the problem
    2. presenting the solutions so a computer can carry out or a human can understand
    3. A computer carries out the solution means it can produce solutions by running programs/softare based on the solutions given/presented in some programming languages

Try It

  • Lets consider the following sequence of numbers. The problem to be solved is to find the largest number:
10 12 8 9 6 15 20 14

Step 1: understanding the problem. This is very important step. We need to know what exactly the problem is. In this case,

  • to find the largest number from the given sequence

Step 2: presenting the solution so a computer or human can understand.

  1. What does it mean by presenting the problem?

    • This means describing the problem in some fashion. For a human to understand, we can use text or diagram.

    • The following is a solution to the finding the largest number problem described in plain but structured English: 

      1  Start from the first number in the list
2       
3  if the first number is larger or equal to the next number
4      make the first number the largest number
5  else
6      make the next number the largest number
7  Move to the next number
8  Repeat the steps 3 to 7 until all the number in the list is compared
9  Output the largest number

    But

  2. How to present the solution so a computer can understand? This is where computer programming languages come to play.
  3. Humans use programming languages to present/describe the solution to a computer. This is called implementation of the solution in programming language.
    1. The following is the implemented solution using Python.

Step 3: Computers follow the instructions from the solution presented to carry out solving the problem. Run the program below and see if the solution works.

<iframe src="https://trinket.io/embed/python/b885a94dd4" width="100%" height="600" frameborder="0" marginwidth="0" marginheight="0" allowfullscreen></iframe>

3 Algorithmic Thinking in Computational Thinking

Learn It

  • In the previous finding the largest number problem, we have learned 3 equally important aspects of problem solving in computing:
    1. understanding the problem
    2. describeing/presenting the solution so a human or a computer can understand
    3. implementing the problem using programming language
  • Lets focus on the step 2: describe/present the solution so a computer/human can understand. We did this by using a sequence of text or plain English but with some structure to make the solution easier for a human to follow.
  • A solution given in step by step instructions is called an algorithm.
  • Algorithmic thinking is to have a solution to a problem, and the solution is such that it can be described in a sequence of instructions.
  • If we have an algorithm, then we can write a program to do it.
  • Computer programs are just algorithms written out in a programming language so computers can understand.

Try It

  • Now, lets apply computational thinking to a simple problem and try to work out step by step. 

    Given a sequence of numbers: 45 67 -9 12 -92 -10 44
Find all positive numbers in the given sequence
  • Try to work out the following by yourself:
    1. understanding the problem.
    2. using algorithmic thinking, and plain but structured English to present a solution to the given problem so your peers can understand.
    3. try to implement the solution you created in step 2 in Python. To implement it, you need:
    4. run the Python program to see if it works.

Badge It - Silver

learning strand: Algorithms

  • Upload your written understanding of the above given problem in plain English to www.bournetolearn.com. Your work must include your understanding of positive numbers.

Badge It - Gold

learning strand: Algorithms

  • Your solution (algorithm) to the problem above in structured English. Upload your work to www.bournetolearn.com.
  • Your algorithm should meet the criteria that it can be understood by a human or for a human to follow to find all positive numbers in a list.

Badge It - Platinum

learning strand: Algorithms

  • Screenshot of your implemented working solution in Python and upload to www.bournetolearn.com