How many zeros are there in billion?

Answer 1

There are two correct answers to this question:

15 (in the USA and in any countries that use "short scale" naming conventions)

Or

24 (in countries that use "long scale" naming conventions)

To work out the number of zeros from the scales:

• Long scale

This is based on powers of a million (106) so multiply the name prefix by 6

→ billion: bi implies 2 → 2 x 6 = 12 zeros

→ trillion: tri implies 3 → 3 x 6 = 18 zeros

→ quadrillion: quad implies 4 → 4 x 6 = 24 zeros

→ quintillion: quin implies 5 → 5 x 6 = 30 zeros

etc

• Short scale

This is based on powers of a thousand (103) plus one, so multiply 3 by the name prefix plus one.

→ billion: bi implies 2 → 3 x (2 + 1) = 3 x 3 = 9 zeros

→ trillion: tri implies 3 → 3 x (3 + 1) = 3 x 4 = 12 zeros

→ quadrillion: quad implies 4 → 3 x (4 + 1) = 3 x 5 = 15 zeros

→ quintillion: quin implies 5 → 3 x (5 + 1) = 3 x 6 = 18 zeros

etc

→ quadrillion: quad implies 4 → 3 x (4 + 1) = 3 x 5 = 15 zeros.

Answer 2

A gazillion.

log base 10 of a zillion.

Answer 3

a zillion minus one

Answer 4

9 zeros ( 1 000 000 000)

Answer 5

5.3