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Comment by jewayne | Hacker News Reader

I have a minor in math, and I don't know what "shrinking by 30X" means. To me, decreases always start from 100%. So I think we are talking about a ~97% decrease in size?

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I don't have a minor in math, and I instinctively thought "shrinking by 30x" means 1/30 of size.

Yeah. "growing" = numerator. "shrinking" = denominator.

It's nice because they're inverses - if you shrink by 30x, then grow by 30x, you're back where you started, whereas a 97% decrease in size followed by a 97% increase in size leaves you at ~6% of the original size.

But "30x" is just another way of saying "3000%". Or, "3000%" is just another way of saying "30x". "Shrinking by 30x" means the same thing as "shrinking by 3000%".

Huh. Downdooted without explanation for correctly explaining how percentages work. Not something I expected on HN. Never change, interwebs!

30x doesn't seem to mean 3000% but means 30 times original value.

If I had starting capital of 100 usd and it increased by 20x then that means I gained 2000 usd which is 20x of my starting capital.

EDIT: correction 30x is same as 3000%.

essentialy yes

I think if you want to say "1/30th of the size", you should say that. Growth is usually measured as a difference. For example, a 200% increase means the value has tripled.

Thanks I hate this, but seems to be everywhere now. "This products is now 3 times cheaper!", WTF. They still haven't got to percentages yet, like 200% off!!.

its more about being more like people say as smaller by 200% isnt as understandable as 30 times smaller

Neither of those makes any sense.

If you try pronouncing that aloud as “…by a factor of 30” it’ll seem less ungrammatical.

> I have a minor in math, and I don't know what "shrinking by 30X" means.

X is input

Y is output

X / 30 = Y

All you need to know, no minor required, as its taught on elementary school (age 11/12 or so?).

So, shrinking by 2x means dividing by 2?

But... doesn't shrinking by 1/2 also mean dividing by 2?

Therefore, 1/2 == 2x ??

I feel like my elementary school math is letting me down somewhere.

Thanks for this note. I'm part of the DockerSlim and Slim.AI ecosystem. Will take this feedback and rework the way we phrase things. Thank you!

this is not valid but its what people say 30 times smaller.

I know and it drives me crazy. "Bigger" and "smaller" express differences, not fractions or multiples.

If I say "image A is 1 MB, image B is 30 times bigger", what is the size of B? I don't think many would respond "31 MB". If you consider it improper to use "bigger" in this way to express a multiple, how would you express that?

Do you know what 'two times smaller' means?

No I don't. That's my point. To me, the number that's two times smaller than x is -x. (x-2x)

I'm no mathematician and it wouldn't often be my choice of phrasing, but it seems unambiguous and clear to me; your definition is much stranger/less intuitive to me.

We're clear on 'x is two times larger than y', right?

    x = 2*y

An equivalent statement is 'y is two times smaller than x', but it conveys a construction more like:

    y = x/2

Which, since we're speaking English sentences, might change the emphasis/implication.

This is really just an English expression that doesn't map perfectly to the actual mathematics it's intended to describe. 2 times smaller does usually mean 1/2 by convention in English and I don't think there's anything more profound than to just say it is what it is.

it means... a lot!

For compression or similar ratio is used.

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