Successor and Predecessor
Every number has a number that comes just after it (called the successor) and a number that comes just before it (called the predecessor). In Class 3, students apply these concepts to numbers up to 1000 and beyond.
Understanding successor and predecessor strengthens number sense and helps with counting, ordering, and comparing numbers.
What is Successor and Predecessor - Class 3 Maths (Numbers)?
The successor of a number is the number that comes right after it. It is found by adding 1.
The predecessor of a number is the number that comes right before it. It is found by subtracting 1.
Successor = Number + 1
Predecessor = Number − 1
Solved Examples
Example 1: Finding Successor of a 3-Digit Number
Question: Find the successor of 456.
Think:
- Successor = 456 + 1 = 457
Answer: The successor of 456 is 457.
Example 2: Finding Predecessor of a 3-Digit Number
Question: Find the predecessor of 300.
Think:
- Predecessor = 300 − 1 = 299
Answer: The predecessor of 300 is 299.
Example 3: Successor at the Boundary (999)
Question: Find the successor of 999.
Think:
- 999 + 1 = 1000
- The successor is a 4-digit number!
Answer: The successor of 999 is 1000.
Example 4: Predecessor at the Boundary (100)
Question: Find the predecessor of 100.
Think:
- 100 − 1 = 99
- The predecessor is a 2-digit number.
Answer: The predecessor of 100 is 99.
Example 5: Finding Both Successor and Predecessor
Question: Find the predecessor and successor of 750.
Think:
- Predecessor = 750 − 1 = 749
- Successor = 750 + 1 = 751
Answer: Predecessor = 749, Successor = 751.
Example 6: Number Between Two Numbers
Question: Ria says a number whose predecessor is 524 and successor is 526. What is the number?
Think:
- Predecessor is 524 → number = 524 + 1 = 525
- Check: successor of 525 = 526 ✓
Answer: The number is 525.
Example 7: Successor of a Round Number
Question: Find the successor of 500.
Think:
- 500 + 1 = 501
Answer: The successor of 500 is 501.
Example 8: Predecessor Ending in 0
Question: Find the predecessor of 610.
Think:
- 610 − 1 = 609
Answer: The predecessor of 610 is 609.
Example 9: Word Problem
Question: Aman's roll number is the successor of 198. Priya's roll number is the predecessor of 200. What are their roll numbers? Are they the same?
Think:
- Aman: 198 + 1 = 199
- Priya: 200 − 1 = 199
Answer: Both have roll number 199. Yes, they are the same.
Key Points to Remember
- Successor = the number that comes just after = number + 1.
- Predecessor = the number that comes just before = number − 1.
- Every whole number (except 0) has a predecessor.
- Every whole number has a successor.
- The predecessor of 1000 is 999. The successor of 999 is 1000.
- Successor and predecessor change the number of digits at boundaries (99→100, 999→1000).
Practice Problems
- Find the successor of 789.
- Find the predecessor of 400.
- Find both the successor and predecessor of 555.
- What number has 699 as its predecessor?
- What number has 501 as its successor?
- Find the successor of 999 and the predecessor of 1000. What do you notice?
- Meera thinks of a number. Its predecessor is 849 and its successor is 851. What is the number?
Frequently Asked Questions
Q1. What is a successor in maths?
The successor of a number is the number that comes right after it. It is found by adding 1. For example, the successor of 45 is 46.
Q2. What is a predecessor in maths?
The predecessor of a number is the number that comes right before it. It is found by subtracting 1. For example, the predecessor of 45 is 44.
Q3. Does every number have a successor?
Yes. Every whole number has a successor. Add 1 to any number to get its successor.
Q4. Does every number have a predecessor?
Every whole number except 0 has a predecessor. The predecessor of 1 is 0. There is no whole number before 0.
Q5. What is the successor of 999?
The successor of 999 is 1000. This is when a 3-digit number becomes a 4-digit number.
Q6. What is the predecessor of 100?
The predecessor of 100 is 99. This is when a 3-digit number goes back to a 2-digit number.
Q7. Can two different numbers have the same successor?
No. Each number has a unique successor. If two numbers had the same successor, they would be the same number.
Q8. Is successor and predecessor covered in NCERT Class 3?
Yes. Successor and predecessor is part of the Numbers chapter in NCERT Class 3 Maths, applied to numbers up to 1000.
