What is 3 × 7?

S1-SA1-0673

Grade Level:

Class 2

Maths, Computing, AI

Definition

What is it?

3 × 7 means adding the number 7 three times, or adding the number 3 seven 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 3 packets of biscuits, and each packet has 7 biscuits. To find out the total number of biscuits you have, you would calculate 3 × 7. This helps you quickly know you have 21 biscuits in total.

Worked Example

Step-by-Step

Let's find the answer to 3 × 7 using repeated addition.

Step 1: Understand what 3 × 7 means. It means adding 7 three times.
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Step 2: Write out the addition: 7 + 7 + 7
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Step 3: Add the first two numbers: 7 + 7 = 14
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Step 4: Add the result to the last number: 14 + 7 = 21
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Answer: So, 3 × 7 = 21.

Why It Matters

Understanding multiplication like 3 × 7 is super important for Maths, Computing, and even AI! In computing, it's used in calculations for game scores or data processing. For AI, it's a building block for complex algorithms that help self-driving cars or facial recognition software work. Learning this now helps you think like a programmer or an AI engineer!

Common Mistakes

MISTAKE: Adding 3 and 7 to get 10 | CORRECTION: Multiplication means repeated addition, not just simple addition. 3 × 7 is 7 + 7 + 7, not 3 + 7.

MISTAKE: Confusing 3 × 7 with 7 × 3 and thinking they are different | CORRECTION: 3 × 7 (three groups of seven) gives the same answer as 7 × 3 (seven groups of three). This is called the commutative property of multiplication.

MISTAKE: Counting incorrectly when doing repeated addition, e.g., 7 + 7 = 15 | CORRECTION: Always double-check your addition carefully. Use your fingers or draw dots if needed to ensure each step of addition is correct.

Practice Questions

Try It Yourself

QUESTION: What is 3 × 5? | ANSWER: 15

QUESTION: If you have 3 rows of mango trees and each row has 8 trees, how many trees are there in total? | ANSWER: 24

QUESTION: A small auto-rickshaw can carry 3 passengers. If 7 auto-rickshaws are full, how many passengers are travelling in total? | ANSWER: 21

MCQ

Quick Quiz

Which of these is the correct way to calculate 3 × 7?

3 + 7

7 + 7 + 7

3 + 3 + 3 + 3 + 3 + 3 + 3

Both B and C

The Correct Answer Is:

3 × 7 means adding 7 three times (7 + 7 + 7) OR adding 3 seven times (3 + 3 + 3 + 3 + 3 + 3 + 3). Both B and C represent this correctly, so D is the right answer.

Real World Connection

In the Real World

When a shopkeeper is counting how many packets of chips they have received from a distributor, they might see 3 cartons, with 7 packets in each. They quickly calculate 3 × 7 to know the total is 21 packets. This helps them manage their stock and sales efficiently, just like apps like Paytm or PhonePe calculate total amounts.

Key Vocabulary

Key Terms

MULTIPLICATION: A quick way to do repeated addition | PRODUCT: The answer you get when you multiply two or more numbers | FACTORS: 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 3 × 7! Next, you should learn about other multiplication tables, like 4 × 7 or 3 × 8. Knowing more multiplication facts will make calculations even faster and help you solve bigger problems easily!