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What is a Certainty (Logic)?
Grade Level:
Pre-School – Class 2
All domains without exception
Definition
What is it?
Certainty in logic means something that is absolutely true and cannot be false. It's a fact or an event that is guaranteed to happen or be true, with no doubt or possibility of being otherwise.
Simple Example
Quick Example
If you buy a 'chai' for 10 rupees and give the shopkeeper a 10-rupee note, it is certain that you will not get any change back. This is because the cost of the chai exactly matches the money you gave.
Worked Example
Step-by-Step
Let's say you have a bag full of only red ladoos.
---1. You reach into the bag without looking.
---2. What colour ladoo will you pick?
---3. Since the bag only has red ladoos, there is no other option.
---4. It is certain that you will pick a red ladoo.
---Answer: Picking a red ladoo is a certainty.
Why It Matters
Understanding certainty helps us make good decisions and solve problems in many subjects like Science, Math, and even everyday life. Scientists use it to prove theories, and engineers use it to build safe structures. This skill is vital for careers in research, law, and even medicine.
Common Mistakes
MISTAKE: Confusing certainty with high probability | CORRECTION: Certainty means 100% sure, no chance of being wrong. High probability means very likely, but still a small chance of not happening.
MISTAKE: Thinking something is certain just because it usually happens | CORRECTION: A certainty must always be true, without exception. If there's even one possible way it could be false, it's not a certainty.
MISTAKE: Believing personal opinions can be certainties | CORRECTION: Certainties are objective facts, true for everyone, regardless of opinion. 'My favourite colour is blue' is an opinion, not a certainty.
Practice Questions
Try It Yourself
QUESTION: Is it certain that the sun will rise from the east tomorrow? | ANSWER: Yes, it is certain.
QUESTION: You have a box with 5 blue pens and 5 red pens. Is it certain that you will pick a blue pen if you close your eyes and pick one? | ANSWER: No, it is not certain. You might pick a red pen.
QUESTION: Your school has a rule that every student must wear a uniform. If Rohan is a student at your school, is it certain that he will wear a uniform to school today? | ANSWER: Yes, it is certain, assuming he follows the school rules.
MCQ
Quick Quiz
Which of the following is an example of a certainty?
It will rain tomorrow.
A coin tossed in the air will land on heads.
If you add 2 and 2, the result will be 4.
My favourite cricket team will win the next match.
The Correct Answer Is:
C
Adding 2 and 2 always results in 4; this is a mathematical fact and therefore a certainty. The other options are probabilities or opinions, not certainties.
Real World Connection
In the Real World
In cricket, when a team needs 1 run to win on the last ball, and the batsman hits a six, it is a certainty that the team will win. Similarly, when booking train tickets online, if the payment is successful and the seat is confirmed, it is a certainty that you have a valid ticket.
Key Vocabulary
Key Terms
FACT: Something known to be true or to have happened | GUARANTEED: Sure to happen or be true | PROBABILITY: The chance of something happening | OBJECTIVE: Not influenced by personal feelings or opinions | LOGIC: A system of reasoning
What's Next
What to Learn Next
Now that you understand certainty, you can explore 'Probability' next. Probability deals with how likely something is to happen, which is closely related to certainty but allows for different levels of likelihood, not just 100%.
