Buffyyour study buddyHi! Ask me about place value, lakhs and crores, the Indian and International systems, or comparing and estimating large numbers.
Buffy is an AI helper and can be wrong — always check your NCERT textbook.
A city of fifty-two lakh, a budget of crores, a population of 140 crore — big numbers are everywhere. Tap each place and see how the Indian system reads them with its 3-then-2 commas.
Play with it
Every digit in a number has a place value. As you move left, each place is ten times bigger. Tap each place to see its value and how the Indian system uses commas to group digits — the last 3, then 2 at a time.
Learn
In the Indian place-value system, digits are read in groups called periods:
Commas group the digits: the last 3 digits first, then 2 digits at a time. So 1,00,000 is one lakh and 1,00,00,000 is one crore.
Worked example. Write 2350000 in the Indian system with commas.
Start from the right. Mark off the last 3 digits: 2350,000. Then take 2 at a time: 23,50,000. So 2350000 = 23,50,000, read as twenty-three lakh fifty thousand.
The two systems name the same number differently:
For example, the same value is 23,50,000 in the Indian system and 2,350,000 in the International system.
Estimating gives a quick, sensible answer without exact arithmetic. To round, look at the digit just to the right of the place you are rounding to: 5 or more rounds up, less than 5 rounds down.
To compare two whole numbers: the one with more digits is bigger. If they have the same number of digits, compare from the highest place value on the left, digit by digit, until they differ.
Where you'll meet it
A big city may have a population of fifty lakh (50,00,000) and India as a whole is home to about 140 crore people. Reading these in the Indian system — lakhs and crores — tells you instantly how large they really are.
A car may cost a few lakh rupees and a house a few crore; government budgets run into thousands of crores. Placing the commas correctly is how you tell ₹2,50,000 from ₹25,00,000 at a glance.
Check yourself
Modelled on the competency-based pattern — MCQ, assertion–reason and a case study, testing whether you can use place value, not just recall it.
Interactive built to the OpenMAIC approach (THU-MAIC, MIT). Content from the NCERT Class 7 Maths textbook, Ganita Prakash (ncert.nic.in).
Buffyyour study buddyBuffy is an AI helper and can be wrong — always check your NCERT textbook.