Computational Thinking Lecture Notes PDF

Computational thinking Problem solving and programming  Lecture 1 Introduction to computational thinking LECTURE OBJECTIVES ❑ Define computational thinking ❑ Computational thinking skills: ▪Decomposition ▪Abstraction ▪Pattern recognition ▪Algorithmic thinking ❑ Writing...

Computational thinking Problem solving and programming  Lecture 1 Introduction to computational thinking LECTURE OBJECTIVES ❑ Define computational thinking ❑ Computational thinking skills: ▪Decomposition ▪Abstraction ▪Pattern recognition ▪Algorithmic thinking ❑ Writing an algorithm for som practical problems Computational Thinking (CT) ❑ CT Computational thinking (CT) is a problem-solving approach using computer, that formulates a problem and its solution to be effectively executed by a computer. (Wing 2014). ❑ CT is a problem-solving approach where the ultimate aim is to provide a solution whose form is ready to be programmed into a computer. How is computational thinking used? ❑ Anyone can apply CT when solving a problem and have a computer play a role in the solution: ▪ Mathematician: carry out long division factoring or doing carries in addition or subtraction. ▪ Scientist: do an experimental procedure. Design thinking model It was designed by the Hasso-Plattner Institute of Design at Stanford University. The main steps of the model is: 1. Empathize: Understand the problem from the audience. 2. Define: Identify the objectives and the decisions that need to be made. 3. Ideate: Brainstorm ideas. 4. Prototype: Design the algorithm solution and check it often. 5. Test: Check your algorithm often throughout the process and go back to previous steps as needed. Design thinking model 7 Some key advantages of developing computational thinking skills: 1.Problem-solving skills: CT equips individuals with a structured approach to problem-solving. It emphasizes breaking down complex problems into smaller, more manageable parts, identifying patterns, and designing algorithms to solve them. 2.Logical reasoning: CT promotes logical reasoning by encouraging individuals to analyze problems, identify cause-and-effect relationships. 3.Creativity and innovation: CT encourages individuals to think creatively and come up with innovative solutions. Some key advantages of developing computational thinking skills: 4. Data analysis and interpretation: CT helps individuals understand how to collect, organize, and analyze data. 5. Algorithmic thinking: CT fosters the ability to design and implement algorithms. Algorithms are step-by-step instructions for solving problems. 6. Collaboration and teamwork: CT often involves working collaboratively on problem-solving tasks. 7. Transferable skills: CT can enhance critical thinking, problem- solving and analytical skills in various fields, including business, healthcare, finance. Computational thinking pillars (skillls) ❑These characteristics will help you to think computationally through a complex problem: Decomposition Abstraction Pattern recognition Algorithmic thinking logical reasoning 1. Decomposition Decomposition is a process of breaking down a big problem into small and manageable parts. The smaller parts can then be solved by the computer, as they are simpler to work with. “If you can’t solve a problem, then there is an easier problem you can solve: find it” George Polya.  Decomposition (Example) Look at an example, the equation to find the roots of a quadratic equation: Decomposition (Example) ❑ On first look, it might appear a little scary, but if we decompose it, we should stand a better chance of solving it: 1) b2 6) 2a 2) 4ac −b + b2 − 4ac 3) b2 - 4ac 7) x= 2𝑎 4) b2 − 4ac −b − b2 − 4ac 8) x= 5) -b ∓ b2 − 4ac 2𝑎 2. Abstraction ❑ Abstraction is about reducing the complexity of a problem or task by focusing on what is important and removing unnecessary details. ❑ It can also be used to have one object stand for many, or to have a word stand for an action. Models and simulations can also be considered abstractions. Abstraction (Example) Find the Represent the Code a Find the important actions run, simulation of a appropriate skills for a stop and hop volcano formula to solve baseball using images. erupting. a physics pitcher. problem. 3. Pattern recognition ❑ It helps to recognize patterns to describe and represent sequences in data or processes. ❑ Find the pattern behind this data: 1, 4, 7, 10, 13, 16, 19, 22, 25,... ❑ Pattern recognition might also involve recognizing shapes, sounds or images. Pattern recognition (Example) 4. Algorithmic thinking ❑ Algorithm is a series of ordered and unambiguous instructions to solve a problem. ❑ Computer scientists seeks to find an effective and efficient algorithm to solve a problem with minimum computing resources (memory or time) while getting the correct output. Algorithm representation The algorithm can be represented using: ▪ Pseudocode: textual representation of an algorithm. ▪ Flowchart: graphical representation of an algorithm. Characteristics of an algorithm An algorithm must possess following characteristics : 1. Finiteness: An algorithm should have finite number of steps and it should end after a finite time. 2. Input: An algorithm may have many inputs or no inputs at all. 3. Output: It should result at least one output and correct. 4. Definiteness: Each step must be clear, well-defined and precise. There should be no any ambiguity. 5. Effectiveness: Each step must be simple and should take a finite amount of time. Guidelines for developing an algorithm 1. An algorithm will be enclosed by START (BEGIN) and STOP (END). 2. To accept data from user, generally used statements are INPUT, READ, GET or OBTAIN. 3. To display result or any message, generally used statements are PRINT, DISPLAY, or WRITE. 4. Generally,COMPUTE or CALCULATE is used while describing mathematical expressions and based on situation relevant operators can be use. Advantages of an algorithm 1.Effective Communication: Since algorithm is written in English like language, it is simple to understand step-by- step solution of the problems. 2.Easy Debugging: Well-designed algorithm makes debugging easy so that we can identify logical error in the program. 3.Easy an Efficient Coding: An algorithm acts as a blueprint of a program and helps during program development. 4.Independent of Programming Language: An algorithm is independent of programming languages and can be easily coded using any high-level language. Office lunch algorithm Problem 1. Determine the final cost for an office lunch for employees given two possible options: $8.50 for a sandwich meal $7.95 for a salad meal The mathematical equation for the total cost is: Cost = 8.5No_sandwiches + 7.95No_salad How many sandwich lunches were ordered? 12 How many salad lunches were ordered? 23 The total cost for the employee lunch is $284.85. Office lunch algorithm (Pseudocode) Step 1: Start Step 2: Read number of sandwiches No_sandwiches Step 3: Read number of salad lunches No_salad Step 4: Calculate Cost = 8.5No_sandwiches + 7.95No_salad Step 5: Print cost Step 6: stop Algorithm for adding two numbers Step 1: Start Step 2: Read two numbers a and b Step 3: Calculate Sum = a + b Step 4: Print sum Step 5: stop Example of an algorithm Algorithm : Calculation of Simple Interest Step 1: Start Step 2: Read principle (P), time (T) and rate (R) Step 3: Calculate I = P*T*R/100 Step 4: Print I as Interest Step 5: Stop Create an algorithm to compute the volume of a sphere. use the formula: v = (4/3) *pi*r3 where pi is equal to 3.1416 approximately. the r is the radius of sphere. display the result. (Design the flowchart) Step 1: Start Step 2: Read r Step 3: Calculate v = (4/3) *pi*r3. Step 4: Print v Step 5: Stop Write an algorithm that converts the input Celsius degree into its equivalent Fahrenheit degree. Use the formula: F = (9/5) *C+32. Step 1: Start Step 2: Read C Step 3: Calculate F = (9/5) *C+32. Step 4: Print F Step 5: Stop Algorithm for find the greater number between two numbers. Step 1: Start Step 2: Read A and B Step 3: if A>B. Step 4: print A Step 5: else Step 6: print B Step 7: Stop  This algorithm has no input Pattern recognition 0, 2, 4, 6, 8, 10, 12, … Step 1: start Step 2: for i=0:99 Step 3: if i%2==0 Step 4: print I Step 5: end for Step 6: stop Questions 1. Define Computational thinking. 2. State the computational thinking skills. 3. List the core concepts of CT. Write an algorithm for  Questions ❑Write an algorithm to compute the radius of a circle. Derive your formula from the given equation: A=πr², then display the output ❑ Determine the most economical quantity to be stocked for each product that a manufacturing company has in its inventory: This quantity, called economic order quantity (EOQ) is calculated as follows: EOQ=2rs/1 where: R= total yearly production requirement S=set up cost per order I=inventory carrying cost per unit. ❑Write an algorithm that takes as input the purchase price of an item (P), its expected number of years of service (Y) and its expected salvage value (S). Then outputs the yearly depreciation for the item (D). Use the formula: D = (P – S) Y. Questions ❑ Design an algorithm to find the circumference of a circle. Use the formula: C=2πr, where π is approximately equivalent 3.1416. ❑Write an algorithm that converts an input inch(es) into its equivalent centimeters. Take note that one inch is equivalent to 2.54cms. ❑Write an algorithm that converts the input dollar to its peso exchange rate equivalent. Assume that the present exchange rate is 51.50 pesos against the dollar. Then display the peso equivalent exchange rate.