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What is Predecessor (Number Before)?
Grade Level:
Class 3
Maths, Computing (decrement)
Definition
What is it?
The predecessor of a number is the number that comes immediately before it. You can find the predecessor by subtracting 1 from the given number. Think of it as taking one step backward on a number line.
Simple Example
Quick Example
Imagine you are watching a cricket match, and the score is 150 runs. If the batsman was out on the previous ball, the score just before that would have been 149 runs. So, 149 is the predecessor of 150.
Worked Example
Step-by-Step
Let's find the predecessor of 75.
1. Identify the given number: The number is 75.
2. Understand what a predecessor is: It's the number just before 75.
3. Apply the rule: To find the predecessor, subtract 1 from the number.
4. Perform the subtraction: 75 - 1.
5. Calculate the result: 74.
So, the predecessor of 75 is 74.
Why It Matters
Understanding predecessors is fundamental to number sense and helps build a strong foundation for more complex math. It's used in computing for 'decrementing' values, like reducing the quantity of items in a shopping cart. Computer programmers and data analysts use this concept regularly.
Common Mistakes
MISTAKE: Adding 1 instead of subtracting 1. | CORRECTION: Remember, 'pre' means before, so you always subtract 1 to go backward.
MISTAKE: Confusing predecessor with successor. | CORRECTION: Predecessor is the number BEFORE (subtract 1), Successor is the number AFTER (add 1).
MISTAKE: Thinking the predecessor of 1 is 0 for natural numbers. | CORRECTION: For natural numbers (counting numbers starting from 1), 1 does not have a predecessor. For whole numbers (starting from 0), the predecessor of 1 is 0.
Practice Questions
Try It Yourself
QUESTION: What is the predecessor of 99? | ANSWER: 98
QUESTION: A train departed from Platform 5. What was the platform number just before Platform 5? | ANSWER: Platform 4
QUESTION: If the current year is 2024, what was the predecessor year? If you were born in that predecessor year, how old would you be this year? | ANSWER: Predecessor year is 2023. You would be 1 year old this year.
MCQ
Quick Quiz
Which of these correctly identifies the predecessor of 101?
100
102
99
110
The Correct Answer Is:
A
The predecessor is the number that comes immediately before the given number. Subtracting 1 from 101 gives 100, so 100 is the predecessor.
Real World Connection
In the Real World
When you use a music player and press the 'previous track' button, the player is essentially finding the predecessor of the current song's position in the playlist. Similarly, when you adjust the volume down on your mobile phone, each click reduces the volume level, finding the predecessor of the current volume setting.
Key Vocabulary
Key Terms
PREDECESSOR: The number that comes immediately before another number | SUBTRACT: To take away one number from another | NUMBER LINE: A visual representation of numbers in order | DECREMENT: To decrease a value by a small amount, often 1
What's Next
What to Learn Next
Now that you understand predecessors, you can easily learn about 'Successor (Number After)'. It's the opposite concept and will help you fully grasp how numbers are ordered and related to each other.
