How many years have passed between the 1800's to the 2000's?

In order to find how many years have passed, all you need to do is subtract 1800 from 2000. Set it up like this:

2000 - 1800 = 200

Therefore, 200 years have passed between the 1800s and the 2000s.

200 years

You can subtract 2000 - 1800 = 200