What's the difference between a percentage of a sum and a percentage less than a sum?

I just watched a report on MSNBC on the gender pay gap. Statistics were reported in the following way:

US women, on average, are earn $0.77 for every dollar earned by men.

Women in least developed countries earn “up to 30% less than men”.

The first statement is fairly easy to understand. It means that US women, on average, earn 77% of US men.

Let’s look at the second statement: I’m not sure how to calculate “30% less”. Wouldn’t it be the same as ”‘as little as’ 70%” of what men make?

This question is not meant to address the gender gap in wages, either in the US or anywhere in the world.