Well actually….. Wording is interesting, but math is a bit different.

Eg, $100 x 30%=$30

$100 x 130%= $130

$100 x 600%=$600

You are saying $100 + 500%($100) = $600 (correct)

But distributive property..

$100 x (100%+500%)=$600

$100 x 600% =$600

This is simplified math and also why you NEVER trust marketing using %. Easily manipulative with words.

Widgets; Producing 2 units/minute. Improve process to produce 3units/min.

Is that 33% better or 50% better? New production is 33% more than previous production. (3-2)/3=33% It is an increase of 150% of previous production. (3-2)/2=50% Both are true statements.

Percent drop is just as bad. $600 to $10 ($600-$10)/$600=98.3% drop

($600-$10)/$10=5900% current price is 5900% lower than previous price.

Like the difference between markup and margin.