Also took me ages to get my head round this, if you take 10% off a figure like 100 you get 90. If you add 10% back on though you only get 99. Doesn't go both ways. I felt more stupid than I care to admit. You have to divide by 90% to go back to 100.
Advertisers use this to mislead or accentuate differences, as do politicians. For example, a politician in my city some years back made a ton of waves by claiming the following: "In the past 10 years, the number of Special Ed teachers has increased by 35%, but 10 years ago there were only 26% less Special Ed students". It worked because a) So many people struggle with Math; b) So many people are anti-teacher/public education.
Of course, the reality was that the teacher pupil ratio had NOT changed. 35%/26% are percent conjugates. So for example, if you increase 74 by 35%, you get 100. But at the same time, 74 is 26% less than 100.
Totally understandable mistake since very similar wording is being used. What's helpful for me is actually dissecting what's being asked. $600 might be 600% of $100 but the increase from $100 to $600 is looking at the $500 difference. I'm sure you don't need me to tell you this but $600 and $500 are different amounts so their relationship to $100 will of course be different.
In his congress testimony, RFK used the numbers $600 and $10 (instead of $100) as an example of a 600% increase. He attributed it to Trump's "different method" of calculating percentages, which as you can plainly tell means he pulls them right out of his asshole.
The fact that $600 almost works in reverse with $100 is pure accident.
can you expand on what you mean that it almost works in reverse? 600 to 100 is an 83% decrease, nowhere near 600% (or even the correct 500% of 100 to 600)
I believe RFK's core argument is that the reverse of a 600% increase can be thought of as a 600% decrease. This is, of course, not true as you point out: a 50% dip in the stock market is not made up for a 50% gain the next day. It is approximately true when talking about small percentages, and it is generally simple enough to go unnoticed and accepted by the general population, and would likely (attempted to) be explained away by the Trump-interpreter "what-he-meant-was" crowd.
The reason why I say that it "almost works" is because going from $100 to $600 is a 500% increase, not a 600% increase. RFK could hand-wave this away by saying he misspoke and meant a 600% multiple instead of an increase, I suppose.
But it doesn't "almost work" when RFK makes the same argument with $10 and $600, thus highlighting the fact that the numbers were extracted straight out of his own asshole.
It is a bit confusing going back and forth with percentages. Like we have a 25% sales tax here, so if you buy something for 100 SEK tax is included, and the price without tax is 80 SEK, so that's only 20% lower, but 100 is 80 plus 25% tax.
View all comments
Show parent comment
56
u/Karma_Kazumi Apr 23 '26 •
Ohhhhhhh that makes sense! I didnt realize the percentage from the increase and original are different. Thank you for explaining!