Unit notes and practice questions
Everything here is for unit 6 of the Grade 9 Information Technology textbook: what the chapter covers, the short notes, practice questions with their answers, and the lesson video where one exists.
The cards filed under this chapter on the Grade 9 Information Technology page. Open one at a time.
When you use it
Use when identifying control structures in flowcharts and algorithms.
Watch out
A diamond symbol by itself is a decision (selection). It only becomes a repetition (loop) if a flow line loops back to an earlier step.
Drafted from Grade 9 Information Technology, page 217 onwards, then checked twice before it went up
| Step | Polya General Method | Computer Science Adaptation |
|---|---|---|
| 1 | Understand the problem | Understand the problem |
| 2 | Make a plan | Develop an algorithm |
| 3 | Execute the plan | Write the program |
| 4 | Review and extend | Test the program |
When you use it
Use when outlining the systematic stages of solving computational problems.
Watch out
Do not write code directly before completing step 2 which is developing the algorithm.
Drafted from Grade 9 Information Technology, page 217 onwards, then checked twice before it went up
| Approach | Starting Point | Core Strategy |
|---|---|---|
| Top-down | General main problem | Decomposes a large problem into smaller manageable modules |
| Bottom-up | Individual small modules | Integrates basic existing modules to build a complete program |
When you use it
Use when choosing a problem-solving strategy for designing complex computer programs.
Watch out
Top-down divides from top to bottom, while bottom-up combines existing small pieces upward into a system.
Drafted from Grade 9 Information Technology, page 217 onwards, then checked twice before it went up
10 multiple-choice questions written against this chapter, each with its answer and the reason. Try one before you open the answer.
Question 1
What is a precise sequence of instructions used to solve a computational problem in a human-understandable format?
Answer: A An algorithm
Why
An algorithm is defined as a precise sequence of well-defined instructions for solving a problem, written in a form that humans can understand.
Question 2
Which flowchart shape is used to represent an Input or Output action?
Answer: B Parallelogram
Why
In standard flowcharts, a parallelogram represents material or information entering (input) or leaving (output) the system.
Question 3
What is the first step in George Polya's classic problem-solving method?
Answer: C Understand the problem
Why
George Polya's four steps begin with step 1: Understand the problem.
Question 4
What type of computational problem has an answer that is strictly Yes or No?
Answer: D A decision problem
Why
A decision problem is a type of computational problem where the only required answer is Yes or No, such as checking if an integer is even.
Question 5
A delivery company in Addis Ababa wants to compute the fastest possible driving route between two locations. Which type of computational problem is this?
Answer: A An optimization problem
Why
An optimization problem seeks the best possible solution, such as finding the fastest or shortest path between locations.
Question 6
In the Flowgorithm software, what is the output of the modulo operation 14 % 3?
Answer: B 2
Why
The modulo operator (%) returns the remainder of integer division. Dividing 14 by 3 gives 4 with a remainder of 2, so 14 % 3 = 2.
Question 7
What are the actors or main movable characters called in the Scratch visual programming environment?
Answer: C Sprites
Why
In Scratch, sprites are the actors or characters that are programmed to perform actions on the stage.
Question 8
What is the process of breaking down a large, complex problem into smaller, manageable sub-problems called in the top-down approach?
Answer: C Modularization
Why
Dividing a bigger problem into smaller sub-problems or modules is known as modularization.
Question 9
When adjusting Polya's problem-solving steps to computer science, which stage directly corresponds to Make a plan?
Answer: B Develop an algorithm
Why
In computer science and IT, step 2 (Make a plan) is represented as developing an algorithm, which acts as the plan for solving the computational problem.
Question 10
A programmer develops separate individual modules to calculate the area of different shapes and then combines them into one large application. Which problem-solving approach is being used?
Answer: B Bottom-up approach
Why
The bottom-up approach starts by designing and solving individual base modules first, and then integrates them together to construct the complete program.
The app holds 12 questions on this unit, marked as you go. These are the first 10.
The whole Grade 9 Information Technology textbook, free as a PDF.
Ministry of Education edition, English, 251 pages
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