Numbers in India and International System (With Comparison)
ICSE Class 6 · Mathematics · Chapter 3
What this chapter covers
- Periods and the Indian system
- The International system
- Reading and writing large numbers
- Comparing the two systems
Key points
- A period is a group of places read together under one name; commas separate the periods.
- The Indian system uses the periods ones, thousands, lakhs and crores.
- In the Indian system, the first comma comes after three digits from the right, and then after every two digits.
- The International system uses the periods ones, thousands, millions and billions, each with three places.
- In the International system, commas come after every three digits from the right.
- 1 lakh = 1,00,000; 1 crore = 1,00,00,000; 1 million = 1,000,000; 1 billion = 1,000,000,000.
- 10 lakh = 1 million, 1 crore = 10 million and 100 crore = 1 billion.
- To read a large number, read each period from the left and say its name; skip a period of zeros.
- To write a numeral, fill every period fully, using zeros where needed.
- To change systems, remove the commas and put them back in the new pattern; the digits do not change.
Questions answered
How many digits are in the ones period, and how many in each later period, in the Indian system?
The ones period has three digits. Every later period (thousands, lakhs, crores) has two digits.
Put commas in 70365012 using the Indian system and then using the International system.
Indian: 7,03,65,012. International: 70,365,012.
Write the number name of 5,08,00,340 in the Indian system.
Five crore eight lakh three hundred forty.
Write the numeral for nine million forty thousand six.
9,040,006.
Write the numeral for two crore seventy lakh eighteen in the Indian system.
2,70,00,018.
How many lakh make one million? How many million make one crore?
Ten lakh make one million. Ten million make one crore.
Meher's family sold a plot of land for ₹ 86,40,000. Write this amount in the International system, in figures and in words.
₹ 8,640,000, which is eight million six hundred forty thousand rupees.
Which is greater, 3 crore or 25 million? Give a reason.
3 crore is greater. 3 crore is 30 million, and 30 million is more than 25 million.