What is 5 × 11?

S1-SA1-0694

Grade Level:

Class 3

Maths, Computing, AI

Definition

What is it?

5 × 11 means adding the number 11 to itself 5 times, or adding the number 5 to itself 11 times. It is a basic multiplication problem that helps us find the total when we have equal groups.

Simple Example

Quick Example

Imagine you have 5 friends, and each friend gives you 11 ladoos. To find the total number of ladoos you have, you would multiply 5 by 11. It's much faster than counting them one by one!

Worked Example

Step-by-Step

Let's find the answer to 5 × 11.

Step 1: Understand that 5 × 11 means 5 groups of 11.
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Step 2: We can write this as repeated addition: 11 + 11 + 11 + 11 + 11.
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Step 3: Add the first two 11s: 11 + 11 = 22.
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Step 4: Add the next 11: 22 + 11 = 33.
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Step 5: Add the next 11: 33 + 11 = 44.
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Step 6: Add the last 11: 44 + 11 = 55.
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Alternatively, you can use the multiplication table for 5 or 11.
We know that 5 multiplied by 10 is 50. So, 5 multiplied by 11 is 5 more than 50.
5 × 11 = 5 × (10 + 1) = (5 × 10) + (5 × 1) = 50 + 5 = 55.

So, 5 × 11 = 55.

Why It Matters

Understanding multiplication is key for many future skills! In Computing, it helps programmers calculate how much memory an app needs. In AI, it's used to process large amounts of data very quickly. Knowing this helps you think like a data analyst or even a game developer.

Common Mistakes

MISTAKE: Adding 5 and 11 to get 16. | CORRECTION: Multiplication is not addition. It means combining equal groups, not just adding two numbers together.

MISTAKE: Forgetting the multiplication tables and trying to count on fingers for large numbers. | CORRECTION: Practice your multiplication tables (especially 5 and 11) regularly. Knowing them by heart makes calculations much faster.

MISTAKE: Getting confused between 5 × 11 and 11 × 5. | CORRECTION: Both 5 × 11 and 11 × 5 give the same answer (55). This is called the commutative property of multiplication, so the order doesn't change the product.

Practice Questions

Try It Yourself

QUESTION: If you buy 5 packets of biscuits, and each packet has 11 biscuits, how many biscuits do you have in total? | ANSWER: 55 biscuits

QUESTION: A small auto-rickshaw charges Rs. 11 for every kilometer. If you travel 5 kilometers, what is the total fare? | ANSWER: Rs. 55

QUESTION: Your school has 5 classrooms. If each classroom has 11 desks, and each desk can seat 2 students, how many students can sit in all classrooms? (First find total desks, then total students) | ANSWER: 110 students (5 x 11 = 55 desks; 55 x 2 = 110 students)

MCQ

Quick Quiz

Which of the following expressions is equivalent to 5 × 11?

5 + 11

11 + 11 + 11 + 11 + 11

5 + 5 + 5 + 5 + 5

5 - 11

The Correct Answer Is:

Option B, '11 + 11 + 11 + 11 + 11', shows 11 added to itself 5 times, which is the definition of 5 × 11. Options A, C, and D represent addition, subtraction, or incorrect repeated addition.

Real World Connection

In the Real World

When you buy groceries, say 5 packs of instant noodles, and each costs Rs. 11, the shopkeeper quickly calculates 5 × 11 to tell you the total bill of Rs. 55. This basic multiplication is used every day in shops, by vendors, and even in apps like Paytm or Google Pay when calculating totals for multiple items.

Key Vocabulary

Key Terms

Multiplication: A quick way to do repeated addition. | Product: The answer you get when you multiply numbers. | Factor: The numbers you multiply together to get a product. | Repeated Addition: Adding the same number multiple times.

What's Next

What to Learn Next

Great job understanding 5 × 11! Next, you can explore other multiplication tables, like 6 × 12 or 7 × 9. This will help you become even faster at mental math and prepare you for more complex problems involving bigger numbers and division.