What is a Fact Family for 4?

S0-SA1-1307

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A fact family for a number like 4 shows all the addition and subtraction sentences that connect three numbers. These three numbers are related to each other, just like a real family. For example, if we have the numbers 1, 3, and 4, we can make different math sentences using only these three numbers.

Simple Example

Quick Example

Imagine you have 4 ladoos. You eat 1 ladoo, and 3 ladoos are left. This shows a relationship: 1 + 3 = 4, and 4 - 1 = 3. These are part of the ladoo fact family!

Worked Example

Step-by-Step

Let's find the fact family for the numbers 1, 3, and 4.

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Step 1: Start with addition. How can we add two of these numbers to get the third? We know 1 + 3 = 4.

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Step 2: Can we swap the numbers in addition? Yes! So, 3 + 1 = 4 is also true.

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Step 3: Now, let's use subtraction. Start with the biggest number, 4. If we take away one of the smaller numbers, we should get the other. So, 4 - 1 = 3.

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Step 4: Finally, if we take away the other small number from 4, we get the first small number. So, 4 - 3 = 1.

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Answer: The fact family for 1, 3, and 4 is:
1 + 3 = 4
3 + 1 = 4
4 - 1 = 3
4 - 3 = 1

Why It Matters

Understanding fact families helps you see how addition and subtraction are connected, making mental math easier. This skill is crucial for everyday tasks like calculating change at a shop or managing your pocket money. It's also a basic building block for careers in finance, engineering, or even managing a small business.

Common Mistakes

MISTAKE: Using numbers that are not part of the 'family' for the specific fact family. | CORRECTION: Always use only the three specific numbers given for that fact family (e.g., 1, 3, and 4 for the fact family for 4).

MISTAKE: Forgetting to write all four possible equations (two addition, two subtraction). | CORRECTION: Remember that a complete fact family usually has four equations, showing all possible relationships between the three numbers.

MISTAKE: Confusing the order in subtraction, like writing 1 - 4 = 3. | CORRECTION: In subtraction, the largest number always comes first when you are finding a positive difference, so it should be 4 - 1 or 4 - 3.

Practice Questions

Try It Yourself

QUESTION: Write the fact family for the numbers 2, 2, and 4. | ANSWER: 2 + 2 = 4, 4 - 2 = 2 (Note: Only two unique equations here because the smaller numbers are the same.)

QUESTION: If the numbers are 0, 4, and 4, what is the fact family? | ANSWER: 0 + 4 = 4, 4 + 0 = 4, 4 - 0 = 4, 4 - 4 = 0

QUESTION: A cricket team scored 4 runs in one over and 0 runs in the next. What is the fact family connecting the runs scored in these two overs with the total runs? | ANSWER: 4 + 0 = 4, 0 + 4 = 4, 4 - 0 = 4, 4 - 4 = 0

MCQ

Quick Quiz

Which of these is NOT part of the fact family for 1, 2, and 3?

1 + 2 = 3

3 - 1 = 2

3 + 1 = 4

2 + 1 = 3

The Correct Answer Is:

Option C (3 + 1 = 4) uses the number 4, which is not part of the original number family (1, 2, 3). All other options correctly use only the numbers 1, 2, and 3.

Real World Connection

In the Real World

When you are splitting a bill for chai with friends, say Rs. 4 total, and two friends pay Rs. 1 and Rs. 3, you are using fact family logic. You know 1 + 3 = 4, and if one friend paid Rs. 1, the other must pay 4 - 1 = 3. This helps manage money easily, whether for daily expenses or even when planning your travel budget for a trip to Goa!

Key Vocabulary

Key Terms

FACT FAMILY: A group of related addition and subtraction equations using the same three numbers. | ADDITION: Combining two or more numbers to find a total. | SUBTRACTION: Taking one number away from another to find the difference. | EQUATION: A mathematical statement showing that two expressions are equal.

What's Next

What to Learn Next

Great job understanding fact families! Now that you know how numbers are related in simple addition and subtraction, you can move on to 'Fact Families for Multiplication and Division'. This will help you see similar connections between multiplying and dividing numbers, building even stronger math skills!