Component 2 - Computer Science ELABORATED EXAM WITH ANSWERS[100% PASS]

Component 2 - Computer Science ELABORATED EXAM WITH ANSWERS[100% PASS] Pick out the three components of computational thinking from the list below. abstraction validation testing decomposition selection algorithmic thinking authentication iteration *Ans* Abstraction, decomposition and algorithmic thinking. What is the name of the process that involves breaking a large problem down into smaller problems that can solved separately? *Ans* Decomposition Aki is shopping for a new pet robot. To choose which one to buy, he thinks: "First, I should ignore how cute it is and just look at the price and how much RAM it has. Second, I should work out the price per GB of RAM and pick the cheapest." What component of computational thinking does each process demonstrate? *Ans* The first process is abstraction - Aki is ignoring the unnecessary details ( cuteness) and focusing on the important ones (price and amount of RAM). The second process is algorithmic thinking - he has a step-by-step method for solving the problem. Kelly is writing a program to find the most commonly used words in a book. Describe how she might use computational thinking to write this program. *Ans* Points you may have mentioned include: - She could use decomposition to break down the problem into sub programs that each perform a specific task. E.g. one part that lists the words and one part that counts how many times they are used. - She could use abstraction to ignore unimportant details like which page the words are on or whether they contain capital letters. - She could se algorithmic thinking by considering the steps she needs to take to get a solution. E.g. count how many times each word is used and then sort them. What is an algorithm? *Ans* An algorithm is a set of step-by-step instructions that can be followed to solve a problem. Give two advantages of presenting an algorithm in pseudocode, rather than in a programming language. *Ans* Any two advantages, e.g. - Pseudocode can be read without knowledge of any specific programming language. - Pseudocode can be easier to write as there is no strict syntax to follow. - It can be easier to convert pseudocode into a programming language than to convert code from one programming language to another. What does this flowchart symbol mean? *Ans* Process - used to show something happening e.g. a calculation What does this flowchart symbol mean? *Ans* Decision - used when a decision has to