What is a Number Fact for 9?

S0-SA1-0652

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A 'number fact' for 9 is a pair of numbers that add up to 9. It shows different ways we can combine two smaller numbers to make 9. These facts help us understand how numbers relate to each other and make calculations easier.

Simple Example

Quick Example

Imagine you have 9 ladoos. If you eat 3 ladoos, how many are left? You have 6 left. So, 3 + 6 = 9 is a number fact for 9. It tells us that 3 and 6 together make 9.

Worked Example

Step-by-Step

Let's find all the number facts for 9:
1. Start with 0. What do you add to 0 to get 9? 0 + 9 = 9.
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2. Next, try 1. What do you add to 1 to get 9? 1 + 8 = 9.
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3. Move to 2. What do you add to 2 to get 9? 2 + 7 = 9.
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4. Continue with 3. What do you add to 3 to get 9? 3 + 6 = 9.
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5. Now 4. What do you add to 4 to get 9? 4 + 5 = 9.
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6. If you try 5, you'll see 5 + 4 = 9, which is already covered (just reversed). The main number facts for 9 are (0,9), (1,8), (2,7), (3,6), (4,5).

Why It Matters

Understanding number facts is super important for building a strong base in maths. It helps you do mental calculations faster and understand addition and subtraction better. This skill is useful for careers like becoming an engineer, a shopkeeper managing inventory, or even a cricket statistician calculating runs.

Common Mistakes

MISTAKE: Only thinking of one way to make 9, like 4 + 5 = 9. | CORRECTION: Remember there are many pairs of numbers that add up to 9, like 0+9, 1+8, 2+7, 3+6, and 4+5.

MISTAKE: Mixing up number facts for different numbers, e.g., saying 2 + 6 = 9 (which is 8). | CORRECTION: Always check that the two numbers you pick actually add up to exactly 9, not more or less.

MISTAKE: Forgetting that 0 can be part of a number fact, like 0 + 9 = 9. | CORRECTION: Always include 0 when listing number facts, as it's a valid number.

Practice Questions

Try It Yourself

QUESTION: Which pair of numbers adds up to 9? (a) 2 and 6 (b) 3 and 5 (c) 1 and 8 | ANSWER: (c) 1 and 8

QUESTION: If you have 9 pens and give away 4, how many do you have left? Which number fact for 9 does this show? | ANSWER: You have 5 pens left. This shows the number fact 4 + 5 = 9.

QUESTION: Rahul scored 9 runs in a cricket match. He hit two boundaries (4 runs each). How many more runs did he score from singles (1 run each)? What number fact for 9 is this? | ANSWER: Two boundaries are 4 + 4 = 8 runs. He scored 9 - 8 = 1 more run from singles. This shows the number fact 8 + 1 = 9.

MCQ

Quick Quiz

Which of these is NOT a number fact for 9?

0 + 9

3 + 6

5 + 3

4 + 5

The Correct Answer Is:

0 + 9 = 9, 3 + 6 = 9, and 4 + 5 = 9 are all number facts for 9. However, 5 + 3 = 8, so it is not a number fact for 9.

Real World Connection

In the Real World

When you buy items at a local kirana store and the shopkeeper quickly calculates your total, they often use number facts in their head! For example, if you buy something for Rs 5 and something else for Rs 4, they instantly know it's Rs 9 without needing a calculator. This mental math is built on understanding number facts.

Key Vocabulary

Key Terms

ADDITION: The process of combining numbers to find their total | SUM: The result of adding two or more numbers | PAIR: Two of something | MENTAL MATH: Doing calculations in your head without writing them down

What's Next

What to Learn Next

Now that you understand number facts for 9, you can explore number facts for other numbers like 10 or 20. This will further strengthen your addition and subtraction skills and prepare you for more complex math problems!