# Hilarious math errors posted on Social Media **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [February 15, 2022, 1:46pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529 "2022-02-15T13:46:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 15, 2022, 4:22pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/21 "2022-02-15T16:22:13Z")
Computers use their own math. 1KB is not a thousand. It’s 1024 binary bytes. 1MB is 1,048,576 binary 1GB is 1,073,741,824 binary ---
**Author:** ![Steve\_MB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steve_mb/32/5339_2.png) [@Steve\_MB](https://boards.straightdope.com/u/Steve_MB)\ **Post date:** [February 15, 2022, 4:26pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/22 "2022-02-15T16:26:01Z")
> [@Thudlow\_Boink](#): > > From the text accompanying “Does 0.4 lbs mean 4 lbs?” It does in Super-Mathematics. [![](https://static.tvtropes.org/pmwiki/pub/images/writers_cannot_do_math.jpg) ](https://static.tvtropes.org/pmwiki/pub/images/writers_cannot_do_math.jpg) ---
**Author:** ![Morgyn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/morgyn/32/3041_2.png) [@Morgyn](https://boards.straightdope.com/u/Morgyn)\ **Post date:** [February 15, 2022, 4:34pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/23 "2022-02-15T16:34:00Z")
> [@k9bfriender](#): > > Multiply 346536 by 987532. I can’t do that in my head, but I _can_ tell you how many digits to expect. I have a sudden, vivid remembrance of Laura Ingalls doing long division in her head for a school exhibition. The divisor and dividend were of comparable length to the numbers in your example. I can’t do either in my head, either. The other day I got a meal at a fast food place. The bill was $12.14, and I handed the cashier $22.14. They kept trying to give me the $2.14 back since, obviously, the $20 would cover the bill. The supervisor eventually had to tell them that I wanted a $10 back. How do kids these days not learn how to do simple arithmetic in their heads to make cash exchanges easier? ---
**Author:** ![Bonum\_Legatum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bonum_legatum/32/6183_2.png) [@Bonum\_Legatum](https://boards.straightdope.com/u/Bonum_Legatum)\ **Post date:** [February 15, 2022, 4:39pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/24 "2022-02-15T16:39:07Z")
> [@k9bfriender](#): > > Multiply 346536 by 987532. I can’t do that in my head, but I _can_ tell you how many digits to expect. But at least you know that it will be about about 350,000,000,000, right? To get even closer, it will be about 346,536,000,000 and then knock off another 1% for the 987… (Yes, I took the STEM track.) ---
**Author:** ![Asuka](https://avatars.discourse-cdn.com/v4/letter/a/dec6dc/32.png) [@Asuka](https://boards.straightdope.com/u/Asuka)\ **Post date:** [February 15, 2022, 4:39pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/25 "2022-02-15T16:39:58Z")
Pauly Shore on a podcast unironically asked “What’s 10 x 3 million?” and even the host was taken aback at how stupid the question was. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [February 15, 2022, 4:40pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/26 "2022-02-15T16:40:29Z")
> [@Morgyn](#): > > The supervisor eventually had to tell them that I wanted a $10 back. How do kids these days not learn how to do simple arithmetic in their heads to make cash exchanges easier? I’ve done reg op, and that’s quite a bit to do more than the math for change. It’s generally not something that is taught in training anymore. Also, given that 2/3rds of sales are plastic nowadays, there is less use and practice at it. > [@Morgyn](#): > > The bill was $12.14, and I handed the cashier $22.14. They kept trying to give me the $2.14 back since, obviously, the $20 would cover the bill. I’ve had plenty of people hand me something like $21.12 in that circumstance as well, thinking they should get a $10 back. It’s not just fast food reg-ops that aren’t great at mental math. ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 15, 2022, 4:42pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/27 "2022-02-15T16:42:24Z")
> [@RickJay](#): > > All evidence is that kids today are BETTER at math, not worse. _All_ evidence? As Morgyn’s example suggests, abject incompetence in simple arithmetic when making change is extremely common, and is most certainly not confined to folks over 25. ---
**Author:** ![Bonum\_Legatum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bonum_legatum/32/6183_2.png) [@Bonum\_Legatum](https://boards.straightdope.com/u/Bonum_Legatum)\ **Post date:** [February 15, 2022, 4:45pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/28 "2022-02-15T16:45:05Z")
I used to do something similar to use up pocket change. For example, if the bill was - say $4.87, I’d give the cashier $5.12 (so my change would just be a 25 cent piece). I’d get a blank stare, so I’d just ask the cashier to run it through the register - “It will come out OK.” Then I’d be asked “Are you a schoolteacher.” But I do have a sympathy for cashiers. There are a lot of con artists trying all sorts of variations to cheat them out of a few dollars. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [February 15, 2022, 4:45pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/29 "2022-02-15T16:45:45Z")
I was telling the story of my landscaping days when my boss tried to take a tree that was over 10,000 lbs over the limit through a weigh station. I mentioned that the fine was $0.10 a lb. Someone pulled out a calculator, punched in some numbers, then exclaimed, “That’s like $1,000!” ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [February 15, 2022, 4:48pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/30 "2022-02-15T16:48:58Z")
> [@3AxisCtrl](#): > > As Morgyn’s example suggests, abject incompetence in simple arithmetic when making change is extremely common, and is most certainly not confined to folks over 25 Two points there. One is that the person working at McDonalds probably isn’t a great example of the brightest in the class, maybe not even a good example of the average student. The other is that, no matter how good you are at math, mental math like that takes practice and pattern recognition, not something taught in schools, but something that gets picked up by using it regularly. If one person a week pays partly with change, it’s not something that someone’s going to pick up on quickly. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [February 15, 2022, 4:50pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/31 "2022-02-15T16:50:52Z")
> [@Bonum\_Legatum](#): > > But I do have a sympathy for cashiers. There are a lot of con artists trying all sorts of variations to cheat them out of a few dollars. Yeah, when I worked reg-op, for every person like you wanting to consolidate change, I had at least 3 or 4 people trying to scam me. If someone is doing something out of the ordinary, it’s better to be suspicious. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [February 15, 2022, 4:55pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/32 "2022-02-15T16:55:04Z")
> [@3AxisCtrl](#): > > As Morgyn’s example suggests, abject incompetence in simple arithmetic when making change is extremely common But is it more common than it used to be? (It might be. Or it might be that, in the old days, someone on the low end of the math skills scale just wouldn’t have had a job where they had to work with numbers, make change, etc.) ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [February 15, 2022, 4:59pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/33 "2022-02-15T16:59:55Z")
I don’t do much mental math anymore. I was just thinking this morning that my calculator history is more embarrassing that my browser history. People can understand why I’d navigate to russianmilf .com, but having to use a calculator to figure that 6X16=96 is something to be ashamed of. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 15, 2022, 5:01pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/34 "2022-02-15T17:01:52Z")
I can remember when cashiers had a sales tax table. I don’t remember exactly, I think up to 25 cents was 1 cent tax. 26 to 50 was 2 cents tax. Over 50 was 3. 1 dollar was 3 cents sales tax for most of my early childhood. They kept it simple because it was done manually. They started actually calculating exact sales tax when the modern cash registers were implemented. Sales tax rates have tripled since my childhood. It’s almost 10% locally. ---
**Author:** ![FrenchDunadan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frenchdunadan/32/5449_2.png) [@FrenchDunadan](https://boards.straightdope.com/u/FrenchDunadan)\ **Post date:** [February 15, 2022, 5:06pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/35 "2022-02-15T17:06:05Z")
With a class of twenty 17-18 years old, they had to calculate the hour rate of pay with '6 hours and 30 minute". Only ONE used 6,5 h the others used 6,3 h… ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 15, 2022, 5:08pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/36 "2022-02-15T17:08:14Z")
Additionally, the internet makes it easy to post every mistake. If that’s all you see you’ll naturally think that nobody is good at math. You can only make that judgement if you look at the billions of numbers that get generated each day and somehow sort out the mistakes. Has that gone up or down or stayed the same over time? Literally nobody knows. Did people in the past make similar errors? Certainly. I actually wrote an article for the January 1983 _Writer’s Digest_ telling authors that they needed to doublecheck their numbers, because typos didn’t pop out at them as with words. Nor did math mistakes or other forms of errors. My bad examples were all from major books and newspapers. Man, I’m old. Don’t get me started on abaci. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [February 15, 2022, 5:10pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/37 "2022-02-15T17:10:30Z")
> [@FrenchDunadan](#): > > With a class of twenty 17-18 years old, they had to calculate the hour rate of pay with '6 hours and 30 minute". Only ONE used 6,5 h the others used 6,3 h… I’ve always felt we needed a metric time system. 10 metric hours in the day, 100 metric minutes in an hour, 100 metric seconds in a minute. That makes the metric seconds slightly shorter than the conventional ones, with 100,000 of them in a day, compared to 86,400 of the old seconds. The problem is that so many physical constants are time based with the old second that it’s a real slog getting people to sign on. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [February 15, 2022, 5:13pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/38 "2022-02-15T17:13:49Z")
I think it’ll probably be easier to change the length of the day than to change the length of a second. ---
**Author:** ![FrenchDunadan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frenchdunadan/32/5449_2.png) [@FrenchDunadan](https://boards.straightdope.com/u/FrenchDunadan)\ **Post date:** [February 15, 2022, 5:16pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/39 "2022-02-15T17:16:58Z")
Hé, we tried it! > **[Decimal time](https://en.wikipedia.org/wiki/Decimal_time)** > > Pages for logged out editors learn more > > Decimal time is the representation of the time of day using units which are decimally related. This term is often used specifically to refer to the time system used in France from 1794 to 1800, during the French Revolution, which divided the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal seconds (100000 decimal seconds per day), as opposed to the more familiar UTC time standard, which... ---
**Author:** ![AlsoNamedBort](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alsonamedbort/32/3213_2.png) [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)\ **Post date:** [February 15, 2022, 5:21pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/40 "2022-02-15T17:21:33Z")
> [@RitterSport](#): > > So, a lot of times when you split a check, the computer still computes the tip on the whole check. So, $18 check, split in half, $9 each. Or, $8.70 _2_ 1.06\*.15 is $2.77. The 1.06 is the tax in NJ – could be more or less. > > But, you protest, you don’t have to tip on the tax! Well, sometimes the computer calculates the tip before tax, sometimes after. Yes, what’s annoying with a lot of these images is that people purposefully cut them off so you can’;t see the whole picture that would make it clearer. For that Circuit City picture, my guess is that originally it was 59.99, then it was 52.99, then 47.99. The “save 12” is based on the original price. [Previous page](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529.md?page=1) [Next page](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529.md?page=3)