Numbers of time we get confused with zeros and numbers. Here I am trying to put all of this so no confusion at all....

First of all taking number in Indian System (system which invented zero '0') and Western system:

Term / Figure / Power Notation / Western system

(Ek) = 1 = 10^0 = 1 (One)

(Das) = 10 = 10^1 = 10 (Ten)

(Sau) = 100 = 10^2 = 100 (Hundred)

(Hazaar) = 1,000 = 10^3 = 1,000 (One thousand)

(Lakh) = 1,00,000 = 10^5 = 100,000 (One hundred thousand)

(Crore) = 1,00,00,000 = 10^7 = 10,000,000 (Ten million)

(Arawb) = 1,00,00,00,000 = 10^9 = 1,000,000,000 (One billion)

(Kharawb) = 1,00,00,00,00,000 = 10^11 = 100,000,000,000 (One hundred billion)

(Neel) = 1,00,00,00,00,00,000 = 10^13 = 10,000,000,000,000 (Ten trillion)

(Padma) = 1,00,00,00,00,00,00,000 = 10^15 = 1,000,000,000,000,000 (One quadrillion)

Now number of zeros use in different numbers:

10 Ten 1 zero

100 Hundred 2 zero

1000 Thousand 3 zero

10000 10 thousand 4 zero

100000 One lakh 5 zero

1000000 One million 6 zero

10,000,000 One crore 7 zero

100,000,000 10 crore 8 zero

Now how many lakh in million, billion and so on.....

10 lakh = 1 million

100 lakh = 10 million = 1 crore

1000 lakh = 100 million = 10 coroe

10,000 lakh = 1000 million = 100 crore = 1 billion

100,000 lakh = 10,000 million = 1000 crore = 10 billion

1 billion = 1000 million Therefore 1 billion = 100 crore or 10000 lakhs

1 trillion = 1000 billion Therefore 1 trillion = 100000 crore or 10000000 lakhs

Now different in the US (English) and the UK (English):

American: Number Notation

Thousand 1,000 10^3

Million 1,000,000 10^6

Billion 1,000,000,000 10^9

Trillion 1,000,000,000,000 10^12

Quadrillion 1,000,000,000,000,000 10^15

Quintillion 1,000,000,000,000,000,000 10^18

English:

Thousand 1,000 10^3

Million 1,000,000 10^6

Thousand Million 1,000,000,000 10^9

Billion 1,000,000,000,000 10^12

Thousand Billion 1,000,000,000,000,000 10^15

Trillion 1,000,000,000,000,000,000 10^18