What is the Predecessor of a Number?

S3-SA4-0285

Grade Level:

Class 6

AI/ML, Data Science, Physics, Economics, Cryptography, Computer Science, Engineering

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.

Simple Example

Quick Example

Imagine you are counting your pocket money. If you have ₹50 today, the amount you had yesterday, which was ₹49, is the predecessor of ₹50. It's just one less than the current amount.

Worked Example

Step-by-Step

Let's find the predecessor of the number 75.

Step 1: Understand what a predecessor is. It's the number just before the given number.

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Step 2: To find the number just before, we need to subtract 1 from the given number.

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Step 3: So, for the number 75, we will calculate 75 - 1.

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Step 4: Performing the subtraction: 75 - 1 = 74.

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The predecessor of 75 is 74.

Why It Matters

Understanding predecessors is fundamental for sequencing data in Computer Science and arranging events in Physics. It's also crucial in Economics for tracking changes over time, like comparing yesterday's stock price to today's. Even in AI, algorithms often work by comparing current data points to previous ones.

Common Mistakes

MISTAKE: Adding 1 instead of subtracting 1. | CORRECTION: Remember, 'pre' means 'before', so you must subtract 1 to find the number that comes earlier.

MISTAKE: Confusing predecessor with successor. | CORRECTION: Predecessor is 'before' (minus 1), while successor is 'after' (plus 1). They are opposite concepts.

MISTAKE: Thinking 0 has no predecessor. | CORRECTION: In whole numbers, 0 has no predecessor. But in integers, the predecessor of 0 is -1. Always consider the number system you are working with.

Practice Questions

Try It Yourself

QUESTION: What is the predecessor of 99? | ANSWER: 98

QUESTION: Your favourite cricket player scored 150 runs today. What was his score just before he reached 150? | ANSWER: 149 runs

QUESTION: A train departed from Platform 5. Before Platform 5, it stopped at Platform 4. What is the predecessor of the platform number the train departed from? | ANSWER: Platform 4

MCQ

Quick Quiz

Which of the following is the predecessor of 405?

406

404

400

504

The Correct Answer Is:

The predecessor of a number is found by subtracting 1 from it. So, 405 - 1 = 404. Options A, C, and D are incorrect as they are not the number immediately preceding 405.

Real World Connection

In the Real World

When you use a music app like JioSaavn or Spotify, the 'previous song' button plays the predecessor in your playlist sequence. Similarly, in a video game, your previous score or level completed is the predecessor to your current one, helping you track progress.

Key Vocabulary

Key Terms

PREDECESSOR: The number immediately before a given number | SUBTRACTION: The process of taking one number away from another | WHOLE NUMBERS: The set of numbers {0, 1, 2, 3, ...} | SUCCESSOR: The number immediately after a given number

What's Next

What to Learn Next

Great job understanding predecessors! Now you're ready to learn about 'Successor of a Number'. It's the opposite concept and will help you understand how numbers are ordered and counted even better.