Class 7 Maths Chapter 1 Large Numbers Around Us | NCERT Solutions (Ganita Prakash)

March 09, 2026

Class 7 Maths Chapter 1 Large Numbers Around Us | NCERT Solutions (Ganita Prakash)

Large numbers appear everywhere in our daily life. From population counts to distances between planets, mathematics helps us understand and represent very big numbers.

In this chapter, we learn about:

Lakh, Crore and Arab
Indian and International number systems
Reading and writing large numbers
Estimation and rounding
Patterns in multiplication
Interesting facts about very large numbers

Understanding large numbers helps students develop number sense and improves problem-solving ability.

1.1 A Lakh Varieties

Farmers in India once preserved nearly one lakh varieties of rice. But how big is one lakh?

Let us understand it step by step.

Pattern of Numbers

Number Type	Example
Largest 3-digit number	999
Smallest 4-digit number	1000
Largest 4-digit number	9999
Smallest 5-digit number	10000
Largest 5-digit number	99999
Smallest 6-digit number	1,00,000

1,00,000 is read as One Lakh

Figure It Out – Solutions

Question 1

Population of Chintamani in 2011 = 75,000

Difference from one lakh:

1,00,000 − 75,000 = 25,000

Answer:

75,000 is 25,000 less than one lakh.

Question 2

Population in 2024 = 1,06,000

Difference from one lakh:

1,06,000 − 1,00,000 = 6,000

Answer:

1,06,000 is 6,000 more than one lakh.

Question 3

Increase in population

1,06,000 − 75,000 = 31,000

Answer:

Population increased by 31,000 people.

Getting a Feel of Large Numbers

Sometimes numbers become easier to understand when we compare them.

Examples:

Height of Statue of Unity ≈ 180 m
Height of Kunchikal waterfall ≈ 450 m

If a building floor is about 4 metres high and there are 10 floors, the building height would be approximately:

10 × 4 = 40 metres

Comparison

Statue of Unity height = 180 m

Building height ≈ 40 m

Difference:

180 − 40 = 140 m

So the statue is 140 metres taller.

Reading and Writing Large Numbers

To make large numbers easy to read, we use commas.

Example:

12,78,830

Number name:

Twelve lakh seventy eight thousand eight hundred thirty

Write Numbers in Words

a) 3,00,600

Three lakh six hundred

b) 5,04,085

Five lakh four thousand eighty five

c) 27,30,000

Twenty seven lakh thirty thousand

d) 70,53,138

Seventy lakh fifty three thousand one hundred thirty eight

Write Numbers from Words

a) One lakh twenty three thousand four hundred fifty six

1,23,456

b) Four lakh seven thousand seven hundred four

4,07,704

c) Fifty lakhs five thousand fifty

50,05,050

d) Ten lakhs two hundred thirty five

10,00,235

1.2 Land of Tens

Imagine calculators with only one button.

Thoughtful Thousands (+1000)

Number	Button Press
3000	3
10000	10
53000	53
90000	90
100000	100

Tedious Tens (+10)

Number	Clicks
500	50
780	78
1000	100
3700	370
10000	1000

Handy Hundreds (+100)

Number	Clicks
400	4
3700	37
10000	100
53000	530
90000	900

Different Ways to Write Numbers

Example:

5072 can be written as:

(50 × 100) + (7 × 10) + (2 × 1)

(5 × 1000) + (72 × 1)

Both expressions equal 5072.

Example Solutions

8300

Method 1

(8 × 1000) + (3 × 100)

Method 2

(5 × 1000) + (33 × 100)

8300

1.3 Crores and Millions

There are two common systems for writing numbers.

Indian System

Number	Name
1,00,000	One lakh
10,00,000	Ten lakhs
1,00,00,000	One crore

International System

Number	Name
100,000	Hundred thousand
1,000,000	One million
1,000,000,000	One billion

Important Facts

1 lakh = 1 followed by 5 zeros

1 crore = 1 followed by 7 zeros

Comparing Numbers

30 thousand < 3 lakhs

500 lakhs > 5 million

800 thousand < 8 million

640 crore < 60 billion

1.4 Exact and Approximate Numbers

In real life, exact numbers are not always necessary.

Example:

Population = 76,068

Instead we may say:

Population ≈ 75,000

This is called approximation.

Rounding Examples

Rounding up example

Students in school = 732

Sweets ordered = 750

Rounding down example

Price = ₹470

Approximate = ₹450

Nearest Numbers Example

For the number 3,87,69,957

Nearest thousand = 3,87,70,000

Nearest ten thousand = 3,87,70,000
Nearest lakh = 3,88,00,000
Nearest ten lakh = 3,90,00,000
Nearest crore = 4,00,00,000

1.5 Patterns in Multiplication

Multiplication Shortcut

116 × 5

= 116 × 10 ÷ 2

= 580

Example

824 × 25

= 824 × 100 ÷ 4

= 20,600

Quick Calculations

2 × 1768 × 50

= 100 × 1768

= 176800

72 × 125

125 = 1000 ÷ 8

= 72 × 1000 ÷ 8

= 9000

125 × 40 × 8 × 25

= (125 × 8) × (40 × 25)

= 1000 × 1000
= 10,00,000

Digit Patterns in Multiplication

2-digit × 2-digit

Product may be:

3 digits
4 digits

Example

10 × 10 = 100

99 × 99 = 9801

So Roxie is correct.

Fascinating Facts with Large Numbers

Purandaradasa composed about

1250 × 380 = 4,75,000 songs

Distance between Earth and Sun

2100 × 70,000

= 147,000,000 km

Water discharged by Amazon River every second

6400 × 62,500

= 400,000,000 litres

1.6 Interesting Questions with Large Numbers

Example

If one bus holds 50 people

1 lakh buses hold

1,00,000 × 50

= 50,00,000 people

But Mumbai population is more than 1 crore.

So the entire population cannot fit in 1 lakh buses.

Fun Thinking Questions

If 250 babies are born every minute:

Babies per day:

250 × 60 × 24

= 3,60,000 babies

So 1 million babies are not born in a day.

Chapter Summary

In this chapter we learned:

• Large numbers like lakh, crore and billion

• Indian and International number systems
• Reading and writing big numbers
• Estimation and rounding
• Multiplication shortcuts
• Patterns in products
• Real life uses of large numbers

Written by the Fuzy Math Team – making numbers your buddy, one chapter at a time.