Logical reasoning | Year 5 Computing PDF Download

What is logical reasoning?

• Definition of Logical Reasoning: Logical reasoning involves following rules that make sense, essentially thinking in a sensible manner.
• Characteristics of Logical Reasoning:
  • Logical reasoning entails thinking sensibly about a problem or situation.
  • It involves coming up with ideas and answers that adhere to logical rules.
• Importance of Logical Reasoning: Logical reasoning is crucial as it allows individuals to use agreed-upon rules to analyze information and solve problems effectively.
• Examples of Logical Reasoning:
  • When faced with a math problem, using logical reasoning would entail applying mathematical principles to arrive at a solution.
  • In a debate, employing logical reasoning involves structuring arguments in a coherent and rational manner.

What are the rules?

• Introduction to Rules: Rules are guidelines that help us understand how to act in different situations.
• Example Scenario: Consider a scenario where a friend wants to wear a spacesuit to school despite the rule requiring a school uniform.
• Logical Reasoning:
  • Logical reasoning involves thinking about the consequences of our actions based on established rules.
  • In the scenario, it's logical to assume that the friend will be noticed by teachers and asked to change into the proper uniform.
• Importance of Following Rules: Following rules is important as it helps maintain order, discipline, and fairness in various settings such as schools.

How Logical Reasoning Impacts Real-World Scenarios

• Ensuring Safety with Logical Rules: In various real-world settings, logical reasoning plays a crucial role in guaranteeing safety measures. For instance, consider a scenario where a rollercoaster's entry gate is computer-controlled and only permits individuals who are 1.5m tall or taller to enter.
• Utilization of Computer Systems: Many safety-critical systems, such as those in amusement parks, utilize computer systems to regulate access and ensure safety protocols are followed. These systems are often interconnected and work in unison to maintain a safe environment for users.
• Role of Logical Rules in Decision-Making: The rollercoaster system mentioned above incorporates a set of logical rules to govern the entry process, ensuring that only individuals meeting the height requirement can access the ride. This logical framework helps in making quick and accurate decisions based on predefined criteria.

How do we use logical reasoning in a computer program?

• The computer that manages the entry gate opens when a person's height exceeds 1.5 meters and closes when it is below 1.5 meters.
• This flowchart depicts how the program is structured.
  
• The program's rules guarantee that only individuals of sufficient height will be allowed through the gates to ride the rollercoaster.

Predicting what will happen

We can employ logical reasoning to anticipate the outcomes when these individuals attempt to pass through the gate.
Examples:
Example 1: Molly is 1.4m tall.
Will Molly get through?
Sol: 
The rule says if the height is less than 1.5m the gate will close.
We know Molly's height is less than 1.5m, so that's easy, the gate will close.
Molly is not tall enough to ride the rollercoaster.

Example 2: Ben is 1.7m tall
Will Ben be allowed through?
Sol:
Ben is 1.7m tall, so logically the entry gate will open for him as he's taller than 1.5m.
Remember, the rule says the gate will open if the height is greater than 1.5m.

Logical Reasoning in Problem Solving

• Using logical reasoning: We apply logical reasoning to tackle issues and troubleshoot programs within a computer-controlled system. By carefully examining the rules in place, we can assess their logic and make adjustments to address problems effectively.
• Example Scenario - Leon's Rollercoaster Ride: Consider Leon, who wants to ride a rollercoaster. The safety rule mandates that riders must be at least 1.5m tall. Leon precisely meets this height requirement.
• Height Requirement: The program specifies that if the height is below 1.5m, the gate closes.
• Analysis:
  • Although Leon is not less than 1.5m, indicating the gate should open, another rule stipulates that the gate only opens if the height exceeds 1.5m.
  • This contradiction leads to a situation where Leon, not surpassing 1.5m, would result in the gate remaining closed.

The program has a bug and the gate system doesn't know whether to open or close.

Changing a program using logical reasoning

• Rule Adjustment: Inclusion of 1.5m Height Criteria: The original rule needs to be updated to accommodate individuals who are exactly 1.5m tall. By incorporating this specific height, we ensure fairness and inclusivity.
• New Rule Formulation: The revised rule can state: "If the height is greater than or equal to 1.5m, allow access."