# 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:** 1
**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, 1:46pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/1 "2022-02-15T13:46:46Z")
This article makes me wonder what is happening in schools today. This article is funny. The most basic reasonable test hasn’t been applied. _Last day as a teenager. Its scary to think when your twenty, you’ve been alive a quarter of a century._ 🎂 Somewhere out there, this kids math teachers are cringing. My favorite example is the incorrect suggested tips on a cash receipt. A quick glance indicates this isn’t reasonable. Round to 9.00. 20% is $1.80. LOL anything more is wrong. Total is 8.70 Suggested tax 15% 3.00 18% 3.60 20% 4.00 Another poster questioned a label on mustard. It’s a 18 oz jar and the label says it’s 50% more than their 12 oz bottle. _The poster asks how that is possible?_ Half of 12 is 6. 12 + 6=18. The label is correct. Other errors are just toe curling. Circuit city clearance was $52.99 now 47.99. You save $12. 😳 That was actually hung in a store? I wonder if this is a symptom of relying on calculators? We were taught to use rounding to estimate and test our answers. Very basic and simple calculations in our heads. > **[40+ People That Need To Go Back To Algebra Class - why these ?](https://whythese.com/badmath/)** > > For many students, few subjects in school could evoke as much despair as the one-word, panic-inducing topic called math. And for some, that fear never truly goes away. There are tons of people of all ages who struggle with math on a daily basis.... ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [February 15, 2022, 2:02pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/2 "2022-02-15T14:02:39Z")
> [@aceplace57](#): > > My favorite example is the incorrect suggested tips on a cash receipt. A quick glance indicates this isn’t reasonable. Round to 9.00. 20% is $1.80. LOL anything more is wrong. > > Total is 8.70 > Suggested tax > 15% 3.00 > 18% 3.60 > 20% 4.00 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. > [@aceplace57](#): > > Circuit city clearance was $52.99 now 47.99. You save $12. 😳 That was actually hung in a store? Well, that’s a pull. ---
**Author:** ![Ponch8](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponch8/32/9883_2.png) [@Ponch8](https://boards.straightdope.com/u/Ponch8)\ **Post date:** [February 15, 2022, 2:04pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/3 "2022-02-15T14:04:48Z")
> [@aceplace57](#): > > _Last day as a teenager. Its scary to think when your twenty, you’ve been alive a quarter of a century._ 🎂 > Somewhere out there, this kids math teachers are cringing. English teachers as well. ---
**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, 2:13pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/4 "2022-02-15T14:13:55Z")
From the text accompanying “Does 0.4 lbs mean 4 lbs?”: > [@](#): > > This individual doesn’t seem to entertain the idea of the use of decimals. For those of you who are still questioning the statement, 0.4 pounds is not the same as 4 pounds. The former weight is lighter than the latter. And yet, in the example directly above it, the writers themselves let slide the extremely common (but, to me, exasperating) error of thinking that 0.75 cents is the same as 75 cents. ---
**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, 2:17pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/5 "2022-02-15T14:17:35Z")
> [@RitterSport](#): > > So, a lot of times when you split a check, the computer still computes the tip on the whole check. That’s a good point. You can get small rounding errors splitting a check. I always tip on the total bill that includes tax. I also round to an even dollar. I wouldn’t tip $1.85. $2 is more respectful. > [@Thudlow\_Boink](#): > > And yet, in the example directly above it, the writers themselves let slide the extremely common (but, to me, exasperating) error of thinking that 0.75 cents is the same as 75 cents Editing a article like this is a minefield. 😉 It is easy to turn numbers upside down when you’re writing. Trying to remember sentence structure, grammar, and get the numberscorrect is challenging. The error with cents bugs me too. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 15, 2022, 2:28pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/6 "2022-02-15T14:28:06Z")
What’s happening in schools is the attitude of students, parents, other (non-math teachers), administrators and the public that it is OK to fail math because math is hard so why even try. ---
**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, 2:28pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/7 "2022-02-15T14:28:48Z")
I was quoting the error. A 20 year old thought he had been alive for a quarter of a century. It’s actually a fifth of a century. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 15, 2022, 2:30pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/8 "2022-02-15T14:30:30Z")
I saw that, but that wasn’t obvious in the OP. I changed my post accordingly. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 15, 2022, 2:32pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/9 "2022-02-15T14:32:31Z")
> [@Thudlow\_Boink](#): > > From the text accompanying “Does 0.4 lbs mean 4 lbs?”: One error I see is students not understanding non-decimal systems. 15 minutes is not 0.15 of an hour. 5 ounces is not 0.5 lb. ---
**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:** [February 15, 2022, 2:35pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/10 "2022-02-15T14:35:22Z")
> [@aceplace57](#): > > Circuit city clearance was $52.99 now 47.99. You save $12. 😳 That was actually hung in a store? I’d be annoyed even if the marked-down price was actually marked $12 off as that’s hardly a “clearance” to me on a $53 item. That said, most clearances these days seem to start at 10%-20% off and only get to what I consider true “clearance” prices (somewhere around a third off to 50%+ off, depending on the item) days later. My favorite of this type of signage was not a math error. I was scanning through the mayonnaise aisle and a conspicuous yellow “SALE!” tag jumped out at me: SALE: $2.99; Original Price: $2.99; You save: $0.00. At least all the math worked out. ---
**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, 2:39pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/11 "2022-02-15T14:39:49Z")
I hear errors like that. I notice many people today don’t use fractions. I prefer saying one-quarter instead of .25. It’s easier for me to divide by 4. .25 of 12 is three. I did that by dividing by 4 instead of manually multiplying .25 x 12. People that grew up with calculators think differently. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [February 15, 2022, 2:45pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/12 "2022-02-15T14:45:59Z")
> [@aceplace57](#): > > I was quoting the error. A 20 year old thought he had been alive for a quarter of a century. > > **It’s actually a fifth of a century.** - I’ll drink to that! ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [February 15, 2022, 2:58pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/13 "2022-02-15T14:58:50Z")
I’ve never seen “suggested tips” on a restaurant receipt figured on anything except the total with tax. I do not tip the tax man. ---
**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, 3:03pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/14 "2022-02-15T15:03:53Z")
This Dr Pepper label doesn’t make sense. There’s 10 calories in 8 oz. So…16 oz would have 20 calories. There should be 25 calories in a 20 oz bottle (1.25 x 20)? They are hoping the consumer will glance at the label and think they’re getting a 10 calorie drink. [![](https://whythese.com/wp-content/uploads/2021/08/Now-thats-just-false-advertising-memeguy.com__img_61068d32d1f1f.jpg) ](https://whythese.com/wp-content/uploads/2021/08/Now-thats-just-false-advertising-memeguy.com__img_61068d32d1f1f.jpg) ---
**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, 3:06pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/15 "2022-02-15T15:06:56Z")
> [@Saint\_Cad](#): > > it is OK to fail math because math is hard so why even try. Anything under 4th grade math is boring repetition and can be done on a calculator. Anything above 4th grade math is an esoteric exercise meant only for geeks and nerds. /s, btw > [@aceplace57](#): > > People that grew up with calculators think differently. Students should learn to do basic arithmetic in their heads, as well as somewhat more complex stuff like multiple digit multiplication and long division on paper, before being allowed to use a calculator. Once those are mastered, a calculator simply speeds things up and reduces errors. If those are not mastered, then one will not realize if the number that their calculator does not match what they _should_ get. Multiply 346536 by 987532. I can’t do that in my head, but I _can_ tell you how many digits to expect. ---
**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:** [February 15, 2022, 3:13pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/16 "2022-02-15T15:13:14Z")
> [@aceplace57](#): > > This Dr Pepper label doesn’t make sense. There’s 10 calories in 8 oz. So…16 oz would have 20 calories. There should be 25 calories in a 20 oz bottle (1.25 x 20)? That’s rounding stuff. I’d have to look it up, but there are rules to how you round off calories, so it may be something like it’s actually 8 or 9 calories for 8 oz rounded to 10 calories, so 20 oz would be 20 calories or 22.5 calories rounded down to 20, respectively. If you read labels, you will find this extremely common. You will see stuff advertised as 0 calories per serving, but the whole bottle might list 5 or 10 calories. ETA: Like, I just dug out a bottle of Gatorade. The bottle says 80 calories for a 12-oz serving, but 170 calories for the whole 24-oz bottle. It’s just rounding. ---
**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, 3:13pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/17 "2022-02-15T15:13:48Z")
> [@aceplace57](#): > > There’s 10 calories in 8 oz. So…16 oz would have 20 calories. There should be 25 calories in a 20 oz bottle (1.25 x 20)? There’s only 20 _Bold Tasting_ calories. The others are regular tasting. ETA: for _my_ math. ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [February 15, 2022, 3:47pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/18 "2022-02-15T15:47:00Z")
> [@aceplace57](#): > > I wonder if this is a symptom of relying on calculators? We were taught to use rounding to estimate and test our answers. Very basic and simple calculations in our heads. They’re still being taught math. All evidence is that kids today are BETTER at math, not worse. My personal peeve is when Facebook pops up questions like: 50+10x0+7+2=A Solve for A The answer is, of course, 59. **Most people get it wrong;** they either forgot the order of operations, just go left to right, and get 9, or don’t know that when you multiply by zero the result is zero, and get 69. But you know who gets it wrong? Old people. Not young people. ---
**Author:** ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)\ **Post date:** [February 15, 2022, 3:48pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/19 "2022-02-15T15:48:28Z")
> [@Thudlow\_Boink](#): > > And yet, in the example directly above it, the writers themselves let slide the extremely common (but, to me, exasperating) error of thinking that 0.75 cents is the same as 75 cents. I saw something like this a few days ago. Someone wanted 4.15 MB of information put on a single DVD which can hold 4.7 MB of data. The person burning the DVD said he would have to use 2 DVDs. Person 1 asked why, 4.15 MB should fit easily on a DVD. Person 2 said it’s simple math, 15 is more than 7. The post did not say if person 2 sent 1 or 2 DVDs. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [February 15, 2022, 4:14pm UTC](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529/20 "2022-02-15T16:14:33Z")
I always thought a whole DVD could hold more than a single 128 kbps MP3 file or a single, moderately sized, jpeg. Man, embarrassing for me! I wonder how they fit a whole movie on them. [Next page](https://boards.straightdope.com/t/hilarious-math-errors-posted-on-social-media/959529.md?page=2)