What is 4 × 9?

S1-SA1-0684

Grade Level:

Class 3

Maths, Computing, AI

Definition

What is it?

4 × 9 means adding the number 9 four times, or adding the number 4 nine times. It is a basic multiplication problem that helps us find the total when we have equal groups.

Simple Example

Quick Example

Imagine you buy 4 packets of biscuits, and each packet has 9 biscuits inside. To find the total number of biscuits, you would calculate 4 × 9. This gives you all the biscuits you have.

Worked Example

Step-by-Step

Let's find the answer to 4 × 9 using repeated addition.
1. We can think of 4 × 9 as adding 9 four times.
2. Start with the first 9: 9
3. Add the second 9: 9 + 9 = 18
4. Add the third 9: 18 + 9 = 27
5. Add the fourth 9: 27 + 9 = 36
--- Alternatively, we can think of it as adding 4 nine times:
1. 4 + 4 = 8
2. 8 + 4 = 12
3. 12 + 4 = 16
4. 16 + 4 = 20
5. 20 + 4 = 24
6. 24 + 4 = 28
7. 28 + 4 = 32
8. 32 + 4 = 36
--- So, 4 × 9 = 36.

Why It Matters

Understanding multiplication like 4 × 9 is super important for everyday calculations and forms the basis for advanced topics. In Computing, it helps with data processing; in AI, it's used in algorithms. Careers like software developer, data analyst, and even a shop owner use multiplication daily.

Common Mistakes

MISTAKE: Adding 4 and 9 to get 13 | CORRECTION: Multiplication means repeated addition, not just simple addition. 4 × 9 means 9 + 9 + 9 + 9, or 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4.

MISTAKE: Forgetting multiplication tables and guessing | CORRECTION: Practice your multiplication tables (like the 4-times and 9-times tables) regularly. Knowing them by heart makes calculations faster and more accurate.

MISTAKE: Confusing multiplication with division | CORRECTION: Multiplication finds the total when you combine equal groups. Division splits a total into equal groups. They are opposite operations.

Practice Questions

Try It Yourself

QUESTION: If a auto-rickshaw driver makes 4 trips and earns Rs. 9 from each trip, how much money does he earn in total? | ANSWER: Rs. 36

QUESTION: Your school has 9 classrooms, and each classroom has 4 windows. How many windows are there in total in the school? | ANSWER: 36 windows

QUESTION: A gardener plants 4 rows of marigold flowers. Each row has 9 flowers. If 5 flowers did not bloom, how many flowers bloomed in total? | ANSWER: 31 flowers (First, 4 × 9 = 36. Then, 36 - 5 = 31)

MCQ

Quick Quiz

Which of these is the correct way to calculate 4 × 9?

4 + 9

9 + 9 + 9 + 9

4 + 4 + 4 + 4

9 - 4

The Correct Answer Is:

Option B (9 + 9 + 9 + 9) correctly shows repeated addition of 9, four times, which is what 4 × 9 means. Option A is simple addition, and Option C is adding 4 four times (which is 4x4), and Option D is subtraction.

Real World Connection

In the Real World

When you buy groceries, if you pick up 4 packs of curd, and each pack costs Rs. 9, the shopkeeper quickly calculates 4 × 9 = Rs. 36 using a calculator or in their mind. This is a common use of multiplication in daily transactions, even with digital payments like UPI.

Key Vocabulary

Key Terms

MULTIPLICATION: A way to find the total when you combine equal groups | PRODUCT: The answer to a multiplication problem | FACTORS: The numbers being multiplied together (e.g., 4 and 9 in 4 × 9) | REPEATED ADDITION: Adding the same number multiple times, which is what multiplication is based on

What's Next

What to Learn Next

Great job understanding 4 × 9! Next, you should learn about other multiplication facts, like 6 × 7 or 8 × 5. This will help you master your multiplication tables and solve even bigger problems with ease.