How many zeros are in a quadrillion?

There are two correct answers to this question:

15 in the USA and other countries using "short scale" naming conventions;

24 in countries using "long scale" naming conventions.

The scales goes as follows:

Value in

Scientific notation

| Short Scale Name |

| Value in numerals

Long Scale Name

10 01oneone10 31,000thousandthousand10 61,000,000millionmillion10 91,000,000,000billionthousand million or milliard10121,000,000,000,000trillionbillion10151,000,000,000,000,000quadrillionthousand billion or billiard10181,000,000,000,000,000,000quintilliontrillion10211,000,000,000,000,000,000,000sextillionthousand trillion or trilliard10241,000,000,000,000,000,000,000,000septillionquadrillion