Names of big numbers
Lakh, crore, arab … and million, billion, trillion … are powers of 10.
Arab or billion?
There are about 1.3 arab starlings in the world. A newspaper abroad would write 1.3 billion. The names are different.
Is an arab bigger than, smaller than, or equal to a billion?
What this lesson covers
The idea
A lakh is 10⁵, a crore 10⁷ and an arab 10⁹, each Indian name being 100 times the previous; a million is 10⁶, a billion 10⁹ and a trillion 10¹², each International name being 1000 times the previous.
Arab or billion?
There are about 1.3 arab starlings in the world. A newspaper abroad would write 1.3 billion. The names are different.
Is an arab bigger than, smaller than, or equal to a billion?
- An arab is bigger
- A billion is bigger
- They are equal
Where do the ladders meet?
Tap a name on the left (Indian) and a name on the right (International). Each name sits at its power of 10. Find where the two ladders meet.
Two ladders of names
A lakh is 10⁵, a crore 10⁷ and an arab 10⁹, each Indian name being 100 times the previous; a million is 10⁶, a billion 10⁹ and a trillion 10¹², each International name being 1000 times the previous.
A hundred crore is an arab: 10² × 10⁷ = 10⁹. Each Indian name adds 2 to the exponent. A thousand million is a billion: 10³ × 10⁶ = 10⁹. Each International name adds 3.
The ladders meet at arab = billion = 10⁹ and at padma = quadrillion = 10¹⁵. The number 10¹⁰⁰ is called a googol.
- Indian | Power | International | Power
- lakh | 10⁵ | million | 10⁶
- crore | 10⁷ | billion | 10⁹
- arab | 10⁹ | trillion | 10¹²
- kharab | 10¹¹ | quadrillion | 10¹⁵
- neel | 10¹³ | quintillion | 10¹⁸
- padma | 10¹⁵
- shankh | 10¹⁷
- maha shankh | 10¹⁹
Notes
A lakh is 10⁵, a crore 10⁷ and an arab 10⁹, each Indian name being 100 times the previous; a million is 10⁶, a billion 10⁹ and a trillion 10¹², each International name being 1000 times the previous.
Check yourself
A kharab is 100 times an arab (10⁹). Which power of 10 is a kharab?
A trillion is 1000 billion (a billion is 10⁹). A trillion is 10 to the power of what?
Answer: 12
1000 × billion = 10³ × 10⁹ = 10¹². So a trillion is 10¹².
How many crore make one arab? (A crore is 10⁷ and an arab is 10⁹.)
Answer: 100
10⁹ ÷ 10⁷ = 10² = 100. So 100 crore make 1 arab.
Which pair of names stands for the same number?
- 10¹⁰. That is only 10 times an arab. 100 = 10², so add 2 to the exponent: 9 + 2.
- 10¹². That would be 1000 times an arab (10³ × 10⁹). 100 is 10², so add 2, not 3.
- 10¹¹ — correct. Yes! 10² × 10⁹ = 10¹¹.
- lakh and million. A lakh is 10⁵ and a million is 10⁶. A million is 10 lakh.
- padma and quadrillion — correct. Yes! Both are 10¹⁵.
- crore and million. A crore is 10⁷ and a million is 10⁶. A crore is 10 million.
- kharab and trillion. A kharab is 10¹¹ and a trillion is 10¹². A trillion is 10 kharab.