What was the percent increase in the population in South America from 1900 to

2000?
in 1900- 38,000,000
in 2000- 515,000,000

I was thinking that I need to divide 515,000,000 by 38,000,000 which is 13.55% but I am not sure.

subtract 38,000,000 from 515,000,000
To get
477,000,000 (See that's the increase)
Now divide 477,000,000 by 38,000,000
to get 12.55
Now move decimal to right 2 places to get 1255%
In other words the population rose by about 12 and one half times.