How many zero does three trillion have?

Answer 1

Using the short-scale "number system" (in the US, UK, etc.):

One thousand (1,000) has three zeros.

One million (1,000,000) has six zeros.

One billion has nine zeros. (Notice it is going up in 3's)

So one trillion has 3+3+3+3=12 zeros.

And because the leading digit does not matter here (three trillion), three trillion also has 12 zeros.

Unfortantely, it's not that easy because there are two "number systems". Because this site has an international audience this needs to be included. I've linked an wikipedia article about the two systems, but if you live in the US you using the short scale system. If you live in the UK you are almost certainly using the short scale system.

Short Scale (US, UK, etc.): One trillion = one million million = 6 + 6 = 12 zeros

Long Scale: One trillion = one million million million = 6 + 6 + 6 = 18 zeros

** Note: the sixes come from the fact that one million has 6 zeros. It is consistent between the two systems.