One More and One Less
One more means adding 1 to a number. One less means taking away 1 from a number. These are the simplest addition and subtraction ideas in Class 1.
If you have 7 marbles and get 1 more, you have 8. If you have 7 and lose 1, you have 6. This concept helps children understand the number line and counting forward/backward.
The idea of one more and one less connects to counting forward and counting backward. When you count forward (1, 2, 3, 4...), each number is one more than the previous. When you count backward (10, 9, 8, 7...), each number is one less than the previous.
This concept also connects to the number line. Moving one step right is one more. Moving one step left is one less.
What is One More and One Less - Class 1 Maths (Numbers up to 100)?
One more than a number is the next number when counting forward. One less than a number is the previous number when counting backward.
One more = number + 1 | One less = number − 1
On a number line:
← one less ... 5 — 6 — 7 ... one more →
Types and Properties
One More and One Less on a Number Line
← one less ... 14 — 15 — 16 — 17 — 18 ... one more →
Special Cases
| Number | One More | One Less |
|---|---|---|
| 0 | 1 | (no number before 0 in Class 1) |
| 9 | 10 | 8 |
| 19 | 20 | 18 |
| 29 | 30 | 28 |
| 99 | 100 | 98 |
Notice that one more than 9 is 10 (moves from 1-digit to 2-digit), and one more than 99 is 100 (moves from 2-digit to 3-digit).
Solved Examples
Example 1: Example 1: One More
Question: What is one more than 5?
Think:
- 5 + 1 = 6
Answer: One more than 5 is 6.
Example 2: Example 2: One Less
Question: What is one less than 9?
Think:
- 9 − 1 = 8
Answer: One less than 9 is 8.
Example 3: Example 3: Bigger Number
Question: What is one more than 19?
Answer: 19 + 1 = 20.
Example 4: Example 4: Word Problem
Question: Ria has 12 pencils. She gets 1 more. How many now?
Answer: 12 + 1 = 13 pencils.
Example 5: Example 5: One Less Word Problem
Question: Aman has 8 chocolates. He gives 1 to his friend. How many are left?
Answer: 8 − 1 = 7 chocolates.
Example 6: Example 6: Number Line
Question: On a number line, what number is one less than 15?
... 13 — 14 — 15 — 16 ...
Answer: One less than 15 is 14.
Example 7: Example 7: Fill in the Blanks
Question: One more than 49 = ___. One less than 50 = ___.
Answer: One more than 49 = 50. One less than 50 = 49. They are the same!
Example 8: Example 8: Fill the Table
Question: Complete this table:
| Number | One Less | One More |
|---|---|---|
| 12 | ? | ? |
| 20 | ? | ? |
| 45 | ? | ? |
Answer:
| Number | One Less | One More |
|---|---|---|
| 12 | 11 | 13 |
| 20 | 19 | 21 |
| 45 | 44 | 46 |
Real-World Applications
Where we use one more and one less:
- Counting: Saying the next number or previous number
- Number before/after: Finding neighbours on a number line
- Simple addition: Adding 1 is the same as finding one more
- Simple subtraction: Subtracting 1 is the same as finding one less
Key Points to Remember
- One more = the next number (add 1).
- One less = the previous number (subtract 1).
- On a number line, one more moves right, one less moves left.
- One more than 9 is 10. One more than 19 is 20. One more than 99 is 100.
- One less than 10 is 9. One less than 20 is 19. One less than 100 is 99.
Practice Problems
- What is one more than 7?
- What is one less than 14?
- Fill in: one more than 25 = ___.
- Fill in: one less than 30 = ___.
- Priya has 16 stickers. She gets 1 more. How many now?
- What is one more than 99?
Frequently Asked Questions
Q1. What does one more mean?
One more means adding 1 to a number. The result is the next counting number. For example, one more than 6 is 7.
Q2. What does one less mean?
One less means taking away 1 from a number. The result is the previous counting number. For example, one less than 6 is 5.
Q3. What is one more than 99?
One more than 99 is 100. This is a special case where we move from a 2-digit number to a 3-digit number.
Q4. What is one less than 1?
One less than 1 is 0. Zero means nothing or no items.
Q5. How does this help with addition?
One more is the simplest form of addition (adding 1). It builds the foundation for adding bigger numbers.
Q6. Can I use a number line to find one more or one less?
Yes. On a number line, move one step to the right for one more and one step to the left for one less.
