# What does "25% less than X" mean ? **URL:** \ **Category:** Factual Questions\ **Created:** [March 25, 2016, 6:07pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151 "2016-03-25T18:07:45Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 28, 2016, 12:23am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/21 "2016-03-28T00:23:55Z")
> [@Snnipe\_70E](#): > > 25 times means multiply first then subtract. How so? Typically, it’s either multiply, or multiply and add, depending on how its phrased. John has 5 cards. Mary has twice as many cards as John. Mary, therefore, has 10 cards. Mary has two times more cards than John. Now, here, it’s a bit of a language issue. It means either Mary has 15 cards or 10 cards. I think most people say it to mean the latter, but the former is the more literal interpretation (as shown in the recent Straight Dope thread on a word problem with this exact issue.) In neither case do I see how multiplication and subtraction comes into it, unless I am misunderstanding what you are saying. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [March 28, 2016, 4:24am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/22 "2016-03-28T04:24:02Z")
> [@pulykamell](#): > > How so? Typically, it’s either multiply, or multiply and add, depending on how its phrased. John has 5 cards. Mary has twice as many cards as John. Mary, therefore, has 10 cards. Mary has two times more cards than John. Now, here, it’s a bit of a language issue. It means either Mary has 15 cards or 10 cards. I think most people say it to mean the latter, but the former is the more literal interpretation (as shown in the recent Straight Dope thread on a word problem with this exact issue.) In neither case do I see how multiplication and subtraction comes into it, unless I am misunderstanding what you are saying. 5 times less or more would imply multiplying by 5. Plain and simple. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [March 28, 2016, 8:09am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/23 "2016-03-28T08:09:05Z")
> [@Absolute](#): > > “Y is 11 times more than X” means Y = 11 \* X “Y is 11 times AS MUCH AS X” means Y = (?) \* X Please tell me what number is represented by (?), when the above statement is true. ---
**Author:** ![bengangmo](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@bengangmo](https://boards.straightdope.com/u/bengangmo)\ **Post date:** [March 28, 2016, 8:51am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/24 "2016-03-28T08:51:37Z")
> [@Snnipe\_70E](#): > > 5 times less or more would imply multiplying by 5. Plain and simple. No — 5 times MORE than 5 times as many as There’s a difference - MORE than means the delta is 5 times the original number That’s why “5 times less than” - while it has slipped into usage as meaning 1/5 is poor construction. Five times less than should actually be X - 5X… which would be (minus) 4X If you want “five times less than” - you should use 20% of or “Only 1/5 of” or if you wanna be dramatic - “tumbled by 4/5” or “plummeted by 80%” ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [March 28, 2016, 9:07am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/25 "2016-03-28T09:07:12Z")
> [@Little\_Nemo](#): > > It’s the opposite of “times more than”. > > A hundred is five times more than twenty. I ask you (essentially) the same question I asked of **Absolute** : How many is five times AS MUCH AS twenty? ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [March 28, 2016, 9:37am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/26 "2016-03-28T09:37:14Z")
> [@bengangmo](#): > > No — > 5 times MORE than > 5 times as many as > > There’s a difference - > MORE than means the delta is 5 times the original number > > That’s why “5 times less than” - while it has slipped into usage as meaning 1/5 is poor construction. > > Five times less than should actually be X - 5X… which would be (minus) 4X > > If you want “five times less than” - you should use 20% of or “Only 1/5 of” or if you wanna be dramatic - “tumbled by 4/5” or “plummeted by 80%” EXACTLY. Using “more than” or “less than” in a comparative statement of quantities means\* that there is a delta between the quantities being compared. Having “(n) times” in the statement means\*\* that the magnitude of that delta is (n) multiplied by whichever quantity is being used as the reference. \*I invite the alert reader to note that I used “means,” and not “implies.” There is a reason for this. \*\* See (\*), above. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 28, 2016, 10:11am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/27 "2016-03-28T10:11:16Z")
“Times less” is like “Divided more”. We could all agree that the form of words means some specific thing, but the words don’t naturally mean the right thing. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 28, 2016, 10:55am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/28 "2016-03-28T10:55:34Z")
Again, regardless of whether it makes sense or not, “X times less than” is unambiguous, because it always means the same thing. How it came to mean that thing might be convoluted, but that’s what it means. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 28, 2016, 12:29pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/29 "2016-03-28T12:29:50Z")
> [@Chronos](#): > > Again, regardless of whether it makes sense or not, “X times less than” is unambiguous, because it always means the same thing. How it came to mean that thing might be convoluted, but that’s what it means. I think that was already abundantly acknowledged. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 28, 2016, 12:50pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/30 "2016-03-28T12:50:04Z")
> [@Snnipe\_70E](#): > > 5 times less or more would imply multiplying by 5. Plain and simple. Well, no, as you see with the responses above, it’s ambiguous. But I’m most curious what you meant by “multiply first then subtract.” Subtract what? ---
**Author:** ![Fool\_in\_the\_Rain](https://avatars.discourse-cdn.com/v4/letter/f/8491ac/32.png) [@Fool\_in\_the\_Rain](https://boards.straightdope.com/u/Fool_in_the_Rain)\ **Post date:** [March 28, 2016, 4:48pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/31 "2016-03-28T16:48:44Z")
> [@Iamnotivan](#): > > Many interesting responses, but the usual expression is "the flu rate this year is 18 times less than last year… 200 pound lesbian dwarfs who rode tan horses more than twice a week for 89 years after dusk were 84 times less likely to contract cancer of the left side eyebrow…meanwhile in Australia, the year the rate of men preferring sheep to roos was 11 times less than in 1492… > > There seems to be a mysterious essential figure missing in the construction(s). Reading that in George Carlin’s newsman voice makes it hilarious! /hijack ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [March 28, 2016, 5:48pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/32 "2016-03-28T17:48:44Z")
> [@Snnipe\_70E](#): > > 25 times means multiply first then subtract. No it doesn’t. For a bunch of reasons. The first reason is that you can’t translate things word for word. Yes, “times” generally means multiply, and “less than” generally means subtract, but putting them together makes a phrase that means “divide by”. The second reason is that it makes plenty of sense that if “x times more than” means multiply by x, then “x times less than” means divide by x. Because division is the reciprocal of multiplication, so if you multiply in the “more” direction, then you divide in the “less” direction. The third reason is that multiply first then subtract will change the sign of your result, which from context almost never makes any sense. When you have a supposedly “ambiguous” phrase with two possible interpretations, and one of them is nonsensical, then it’s not really that ambiguous. I say “I just flew in from New York” this morning, that phrase isn’t ambiguous because I didn’t specify that it was on a plane. Because the other interpretations are silly. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [March 29, 2016, 3:43pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/33 "2016-03-29T15:43:56Z")
It is a sign of general innumeracy. Even when I know what the words mean, I can’t assume the author did, so I still don’t know for certain what they meant. The unambiguous construction is “X is 5% of Y” The common construction is “X is 95% less than Y”. “X is 20 times less than Y” is just pathetic. “X is 1/20th Y” is clear. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [March 29, 2016, 4:21pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/34 "2016-03-29T16:21:57Z")
If “five times more than 20” is 5 x 20 = 100 what is “fifty percent more than 20?” Using the same logic it’s 10, which is clearly wrong. However, if “five times more than 20” means 5 x 20 + 20 = 120. Then “fifty percent more than 20” mean 0.5 \* 20 + 20 = 30. Which is clearly what is meant. ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [March 29, 2016, 5:15pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/35 "2016-03-29T17:15:36Z")
> [@Kevbo](#): > > “X is 20 times less than Y” is just pathetic. “X is 1/20th Y” is clear. People seem to really dislike this phrasing, but that doesn’t make it > [@Snarky\_Kong](#): > > If “five times more than 20” is 5 x 20 = 100 what is “fifty percent more than 20?” Using the same logic it’s 10, which is clearly wrong. > > However, if “five times more than 20” means 5 x 20 + 20 = 120. Then “fifty percent more than 20” mean 0.5 \* 20 + 20 = 30. Which is clearly what is meant. English is not a context free grammar. There really is no reason that “x % more than y” has to be parsed in exactly the same way as “x times more than y”. Both are unambiguous and reasonable in normal conversation. They simply aren’t consistent with each other. x% more than y means Y + x/100 x times more than y means x \* y x times less than y means y / x ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [March 29, 2016, 8:10pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/36 "2016-03-29T20:10:48Z")
Just change your language. If something is “twice as slow” just say it’s “half as fast”. The only people who ever write ambiguous statements like these are journalists who don’t know math. I’ve never seen a legit scientist, engineer, or mathematician say “five times less”, unless something happened 100 times yesterday, and today it happened 95 times, or “five times less”. Percentage wise, it makes sense. 25% less is 75% of the original number. Of course, when you’re talking percentages of percentages, you get more ambiguity, so don’t do that. Just say “the likelihood of rain increased to 50% today, up from 25% yesterday”. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [April 1, 2016, 3:02am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/37 "2016-04-01T03:02:14Z")
> [@iamthewalrus\_3](#): > > People seem to really dislike this phrasing, but that doesn’t make it > > English is not a context free grammar. There really is no reason that “x % more than y” has to be parsed in exactly the same way as “x times more than y”. Both are unambiguous and reasonable in normal conversation. They simply aren’t consistent with each other. > > x% more than y means Y + x/100 > x times more than y means x \* y > x times less than y means y / x “2 times more than” is not unambiguous. ---
**Author:** ![bengangmo](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@bengangmo](https://boards.straightdope.com/u/bengangmo)\ **Post date:** [April 1, 2016, 9:11am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/38 "2016-04-01T09:11:28Z")
> [@iamthewalrus\_3](#): > > People seem to really dislike this phrasing, but that doesn’t make it > > English is not a context free grammar. There really is no reason that “x % more than y” has to be parsed in exactly the same way as “x times more than y”. Both are unambiguous and reasonable in normal conversation. They simply aren’t consistent with each other. > > x% more than y means Y + x/100 > x times more than y means x \* y > x times less than y means y / x this is utter tripe and uncontrovertibly wrong MORE THAN means the difference between the two 50% more than 100 is 150. Just substitute in numbers to see why Today there are 5 times MORE people in the office than yesterday there are 500% more people than yesterday So there are 600 people in the office today ---
**Author:** ![bengangmo](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@bengangmo](https://boards.straightdope.com/u/bengangmo)\ **Post date:** [April 1, 2016, 9:24am UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/39 "2016-04-01T09:24:08Z")
> [@DrCube](#): > > Just change your language. If something is “twice as slow” just say it’s “half as fast”. The only people who ever write ambiguous statements like these are journalists who don’t know math. I’ve never seen a legit scientist, engineer, or mathematician say “five times less”, unless something happened 100 times yesterday, and today it happened 95 times, or “five times less”. > > Percentage wise, it makes sense. 25% less is 75% of the original number. Of course, when you’re talking percentages of percentages, you get more ambiguity, so don’t do that. Just say “the likelihood of rain increased to 50% today, up from 25% yesterday”. You could also say that rain is twice as likely today as yesterday. Or the likelihood of rain has doubled This is actually one of my pet peeves and I hate imprecision is math…once this sort of thing starts to slip into common usage, and words stop having meaning - then the whole thing goes downhill. You can already see here that while nobody is misunderstanding the actual meaning of “5 times less than”, SOME people are trying to use the reverse logic for 5 times more than - which is wrong wrong wrong. And if we take “5 times more than” to mean the same as “5 times less than” - how then do we explain percentages? My wife’s pay is 120% of mine My wife gets paid 20% more than me My brother earns 240% of my meager salary my brother earns almost 2.5 times my salary. My brother earns 1.4 times more than me. All are easily understandable if you the words don’t shift in meaning Once you allow the words to slip around then you get confusion - which makes math harder to understand, not easier. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [April 1, 2016, 12:55pm UTC](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151/40 "2016-04-01T12:55:29Z")
The problem is, as much as I agree with you **benganmo** and that’s exactly how I solved that one word problem that was in a similar thread (about “what two times more” means in a word problem involving someone running four laps, i.e., that it’s 12), I actually can’t find any written usage in a cursory Google news search that shows anybody using “two times more” or such constructions to mean anything but “twice as many as.” So it appears the war has long been over and “two times more” means “twice as many as,” although I personally avoid “X times more” constructions all together. [Previous page](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151.md?page=1) [Next page](https://boards.straightdope.com/t/what-does-25-less-than-x-mean/750151.md?page=3)