What is a Number Fact for 8?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A number fact for 8 is any mathematical equation (like addition, subtraction, multiplication, or division) where the numbers involved combine to give 8 as the result or are directly related to 8. It helps us understand different ways to make or break down the number 8.

Simple Example

Quick Example

Imagine you have 8 laddoos. You can give 5 laddoos to your friend and keep 3 for yourself. This is a number fact: 5 + 3 = 8. Or, if you started with 8 laddoos and ate 2, you'd have 6 left: 8 - 2 = 6. These are different ways to see the number 8.

Worked Example

Step-by-Step

Let's find some addition number facts for 8.
1. Start with 0. How many more do we need to make 8? 0 + 8 = 8.
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2. Start with 1. How many more do we need to make 8? Count up from 1 to 8: 1, 2, 3, 4, 5, 6, 7, 8. That's 7 more. So, 1 + 7 = 8.
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3. Start with 2. How many more do we need to make 8? Count up from 2 to 8: 2, 3, 4, 5, 6, 7, 8. That's 6 more. So, 2 + 6 = 8.
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4. Start with 3. How many more do we need to make 8? Count up from 3 to 8: 3, 4, 5, 6, 7, 8. That's 5 more. So, 3 + 5 = 8.
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5. Start with 4. How many more do we need to make 8? Count up from 4 to 8: 4, 5, 6, 7, 8. That's 4 more. So, 4 + 4 = 8.
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These are some addition number facts for 8: 0+8=8, 1+7=8, 2+6=8, 3+5=8, 4+4=8.

Why It Matters

Understanding number facts helps you do mental math quickly and easily, like calculating change at a shop or splitting a bill. It's crucial for everyday tasks and forms the base for higher mathematics. This skill is vital for careers like a shopkeeper, a cashier, or even an engineer who needs to quickly estimate calculations.

Common Mistakes

MISTAKE: Only thinking of addition facts for 8, like 4+4=8. | CORRECTION: Remember that subtraction, multiplication, and division facts also count. For example, 10 - 2 = 8 is a subtraction fact for 8.

MISTAKE: Confusing number facts with multiples. For example, saying 16 is a number fact for 8 because 8 x 2 = 16. | CORRECTION: A number fact for 8 means the result is 8, or 8 is directly involved in a related way (like 8 divided by 1 is 8). 16 is a multiple of 8, not a number fact *for* 8.

MISTAKE: Forgetting that the order of numbers in addition doesn't change the fact (e.g., 3+5=8 is the same as 5+3=8). | CORRECTION: While 3+5=8 and 5+3=8 are both valid, they represent the same core addition fact. Focus on unique pairs of numbers that add up to 8.

Practice Questions

Try It Yourself

QUESTION: Name two numbers that subtract to give 8. | ANSWER: 9 - 1 = 8 (or 10 - 2 = 8, etc.)

QUESTION: You have 8 chocolates. If you share them equally among two friends, how many does each friend get? What number fact is this? | ANSWER: Each friend gets 4 chocolates. This is a division fact: 8 / 2 = 4.

QUESTION: A cricket team scored 8 runs in an over. If they scored 3 runs from boundaries (fours) and the rest were singles, how many singles did they score? Write this as a number fact. | ANSWER: They scored 5 singles. This is a subtraction fact: 8 - 3 = 5 (or an addition fact: 3 + 5 = 8).

MCQ

Quick Quiz

Which of these is NOT a number fact for 8?

4 + 4 = 8

16 / 2 = 8

8 x 1 = 8

8 + 8 = 16

The Correct Answer Is:

Options A, B, and C all result in 8 or show 8 as a direct component of the equation. Option D results in 16, not 8, so it is not a number fact for 8.

Real World Connection

In the Real World

When a shopkeeper gives you change after you buy something, they quickly use number facts. For example, if an item costs Rs 7 and you give Rs 15, they mentally calculate 15 - 7 = 8 to give you Rs 8 back. This quick calculation relies on knowing number facts.

Key Vocabulary

Key Terms

FACT: A piece of information known to be true. | EQUATION: A statement that two mathematical expressions are equal. | ADDITION: Combining numbers to find a total. | SUBTRACTION: Taking one number away from another. | MULTIPLICATION: Repeated addition of the same number.

What's Next

What to Learn Next

Great job learning number facts! Now that you understand how to make and break down the number 8, you can explore number facts for other numbers like 9, 10, or 20. This will make your mental math even stronger and prepare you for bigger calculations!