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Writers Cannot Do Math

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In Super-math it may be 32,000. But in regular math, it's 3,200.note 

Up in the sky, the alien mother ship sent down twenty hundred troops, three in each space jet.
And if you want to know how many jets there were, you can do the math yourself. I'm a very busy writer trying to make a movie here.
Calvin and Hobbes II: Lost at Sea (a Script Fic that imitates a movie)

You're watching a show or movie, or reading a book, when suddenly something numerical throws you for a slight curve — like a date, or a character's age. Your brow furrows. You start ticking things off on your fingers. What the hell? That wasn't right!

You have just discovered the fundamental truth: that your favorite author failed irredeemably at high school math and never wants to see a number ever again except in the corner of a page. This is a particular kind of continuity error that would be avoided if professional writers kept calculators at their desks. It can also come from multiple writers not checking with each other, or screwups in the timeline.

Compare Soap Opera Rapid Aging Syndrome, Not Allowed to Grow Up, and Longest Pregnancy Ever, where the writers can do math — they're just intentionally fudging it. See also Sci-Fi Writers Have No Sense of Scale and Not Drawn to Scale. Possibly the root cause of Everybody Hates Mathematics. Might even involve E = MC Hammer. Artistic License – Statistics is a subtrope.


A natural habitat of the MST3K Mantra and Fan Wank, as in many cases, these errors are not important for the plot (even when they are).

Oh, for the examples below that reference the number Pi, it is an irrational number with no limit — an endless number — of digits, but the first 16 are 3.141592653589793. Also, the first thirty-two for the square root of pi are 1.7724538509055160272981674833411.



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    Comic Strips 
  • The Dick Tracy story "The Man of a Million Faces" features a string of bank robberies committed by celebrity lookalikes — or is it a single master of disguise? The story makes a big deal of using known heights of objects to measure (they mean "calculate") the perpetrator's height, which turns out to be a consistent 5'11". Yet a previous diagram shows a line labeled 69.9" going over his head with room to spare.
    • Presumably the writer forgot that there were 12 inches to a foot, not 10.
  • Another Dick Tracy story involves thieves stealing small-valued coins from parking meters. Now, $2 in nickels is only 40 coins, far less than the large handful shown, whereas when Larry throws $20 in pennies onto his mother's stomach, the size of the bag pictured is about right, but that would seriously hurt.

    Film — Animation 
  • Beauty and the Beast:
    • According to a lyric in "Be Our Guest", the castle has been under the Enchantress's curse for 10 years. Since the rose stopped blooming once the Beast turned 21, this would mean that he was 11 years old when he was cursed. This does not match up with the stained glass windows in the prologue or the portrait of his human form in the West Wing, which show him as a young adult (not to mention that the curse comes off as a lot crueler if he was a child when he was affected).
    • Another issue up for debate is the span of time over which the main events of the movie take place. The movie appears to start in autumn ("Belle"), then quickly goes into winter (the "Gaston" reprise). The famous title song dance scene takes place on a warm night (complete with crickets chirping), yet that same night after Belle is released, there is still a foot of snow on the ground. Later that same night, there is a torrential thunderstorm, suggesting that it is spring, which means LeFou would have been waiting for Belle and Maurice to come home for the entire winter.
    • Maurice sets out for the castle to save Belle when the Beast is still animalistic and unrefined. When Belle looks into the mirror and sees him out in the woods, the Beast has become gentler and has fallen in love with Belle. Does that mean Maurice was out in the woods for weeks or months on end, or was the Beast reformed in the span of one or two days?
    • The various direct-to-video films and other follow-ups don't help with this issue. Enough time passes in the castle that they celebrate Christmas, for instance. The Perspective Flip novel The Beast Within scraps the movie's implication that the Beast was cursed when he was only eleven years old, but keeps the condition of the curse becoming permanent when he turns 21. But it's not clear at all how much time passes over the course of the story — he is old enough to be engaged when he's cursed, several months pass as the curse begins to take effect, and years pass after that. Thus the Beast's age remains in doubt.

    Films — Live-Action 
  • π:
    • Mathematician/genius Max Cohen tells the Kabbalists that he can't just tell them the 216 digit MacGuffin number because "You've already written down every 216 digit number and intoned them all and what has it gotten you?" To do so would, of course, take even a large group of researchers, such as the entire population of the Earth, significantly longer than the age of the Universe to do, and inconceivably more ink than there is mass in the universe — indeed, even if only one electron were needed to write down each number, 10^100 universes would be much too small. Any mathematician should be well aware of this. Of course, Max and reality don't always see eye to eye, especially considering he's having a schizophrenic breakdown at that point.
    • Also, the Kabbalists are after it because they're looking for a 216 character word. Since this would be in Hebrew, which has 22 characters, they actually want a number with roughly 290 digits. So Max probably doesn't even have what they want.
    • Max also describes the golden ratio by writing a:b::a:a+b. He means a:b::b:a+b; the version he wrote immediately gives b=a+b, so a=0. (Interestingly, this error isn't in the script.)
  • In Captain America (1990) the boy who would become The Red Skull is kidnapped by government agents to make him a super soldier, it is stated that seven years pass when Captain America comes to rescue him by this point he appears to be in his mid-late twenties, this doesn't add up at all because if he was abducted when he was 10 the oldest he'd be is 17.
  • Judge Dredd gives the crime rate in Mega-City One in Dredd as "Twelve serious crimes reported every minute. Seventeen thousand per day." This is obviously meant to sound astonishingly high to the audience, but at the same time the city has a population of over 800 million. Doing the math, that means about 780 "serious crimes" per 100 000 residents per year (which is a standard method of expressing crime rates). In comparison, the violent crime in New York city was considered high in the 1980s, that number hovered around 900-1100, while 2010 had a "historical low" of 581. Of course, we do not know what exactly is considered a "serious crime" in Mega-City One or the number of crimes that just go unreported, which seems rather high based on the comics.
  • Aliens:
    • There are several problems with the Director's Cut, which restores several scenes. The first is that there are only about 150 colonists on the planet, which means a maximum of about 150 aliens (it's unclear how many colonists were not successfully impregnated and died other ways). This isn't too bad a problem with the theatrical cut, but the Director's Cut includes scenes of 4 Sentry Guns with 500 rounds apiece blasting away at the aliens when they attack in a Zerg Rush, with the camera showing scores of aliens killed. There are also plenty of aliens killed throughout the rest of the movie by the Marines. And yet, when attempting to escape, the motion trackers light up with what looks to be 50-100 aliens at least converging upon them.
    • Also, the same scene that introduces the Sentry Guns also shows the remaining marines only have about 50 rounds apiece in their rifles, yet they clearly fire way more than that when they try to rescue Ripley from the Med Bay and in the subsequent base assault and retreat through the air shafts.
    • Both versions of the film also have the alien attack on their sealed base, while Hudson is reading the distance to the closest target. When he reaches 6 meters, they start arguing because they realize that the aliens would be inside the room at that point. Problem is, Hudson keeps counting down the distance before they get their realization that the aliens are coming from above and/or below them, getting down to 3-4 meters. The marines then spend a good 10-20 seconds realizing what's up and figuring out a way to take a look in the shaft above the ceiling. Apparently, the aliens decided to be good sports and stopped moving while they were discussing matters, or the writers didn't think that anything less than 2 meters is basically within touch range and Hicks wasn't going to get a chance to look above the ceiling tiles.
  • Entrapment: Catherine Zeta-Jones needs ten extra seconds after midnight in order to use a computer program to steal billions of dollars from an international bank. After 11pm, a device she set up "steals" 1/10th of a second every minute until midnight, which will total 10 seconds by midnight. But that only equals 6 seconds, which is 4 shy of the required 10.
  • In Forrest Gump, Forrest claims that Jenny died on a Saturday, and yet her gravestone says 22 March 1982, which was a Monday. Odd that Robert Zemeckis would make that mistake, considering he so thoroughly avoided it in the Back to the Future films.
  • The prologue of the original Halloween takes place in 1963 and Michael is explicitly six years old. The rest of the film takes place in 1978, and yet the credits list Tony Moran as playing "Michael Myers (age 23)." He should, of course, be 21.
  • The Heavenly Kid has the title character die in what is clearly the late '50s or early '60s. He's then brought up to The Present Day (1985) and discovers he sired a son, who's now in High School. Apparently, his son had to repeat a few years.
  • In Home Alone, Kevin is 8 years old; in Home Alone 2, Kevin is 10, the same age as actor Macaulay Culkin, who plays him, was at the time of filming; that is, the sequel was made two years after the original. But it was set exactly one year later. Either his birthday occurs over the course of both movies (and nobody bothers to mention it), or he should be 9.
  • It's a Wonderful Life:
    • Clarence says that, in the altered reality, Harry Bailey died at the age of nine, but the gravestone right in front of him as he says the line reads "1911 - 1919", making him either 7 or 8.
    • Clarence implies that he was a contemporary of Mark Twain, then later calculates his age as 293 ("next May"). That would have put his birth in 1653: many, many years before Mark Twain.
  • In the James Bond movie Goldeneye, the Big Bad seeks revenge against the British government for betraying his parents at the end of World War II (leading to their deaths), then figuring he would be too young to remember. Seeing as how he's roughly the same age as Bond (somewhere from mid-30s to early 40s), he's too young to exist before then.
    • This was averted in the 2010 Wii remake of the original game of the movie: since the game is set in the present day, said Big Bad's motivation is changed to outrage over the 2008 Financial Crisis and the complicity between his former employers and the bankers that caused it.
    • This is a misconception; the villain's parents survived Stalin's executions and his father killed his mother in a murder-suicide out of survivors guilt; however, it is never stated when the father did this or the guilt was too much for him, and could have been years or even decades later, by which time the Big Bad could indeed have been born.
    • It should be noted that the character was originally written as a mentor figure to Bond, with Alan Rickman and Anthony Hopkins both considered, who would have both been the right age.
  • Kelly's Heroes, a World War II film, features a bank heist of 14,000 bars of Nazi Gold supposedly worth $16 million in 1944 dollars. No matter how you do the math, these figures cannot be reconciled with (a) the number of shares, (b) the observed weight and size of the bars, (c) the number of boxes. See the Headscratchers.Kellys Heroes page for all the gory details.
  • Mamma Mia! has a real doozy; it is set in the modern era, as the clothing of the main characters and a line about a "web site" would indicate. At the earliest it would have to be set in about 1998, when advertising your business via the Internet became a thing. The film revolves around a 20-year-old girl trying to find out which of three men is her birth father, meaning she would have been conceived, again, at the earliest, in 1976 (but probably as much as a decade later, as nothing indicates the film isn't set in the same time period as when it was released, in 2008). However, many lines of dialogue, and one song, indicates that her mother met these three men during the early to mid-sixties (Pierce Brosnan's character dressed like a hippie when younger, plus Stellan Skarsgaard's character out-and-out states that "those crazy years, that was the time of the flower power"). This is also consistent with the fact that Meryl Streep, Christine Baranski and Julie Walters play "childhood friends" who were apparently also a short-lived singing group in the sixties meaning that they would have had to be at least in their late teens by then, and all three of them (and all three of the potential fathers) appear to be somewhere in their mid- to late-fifties. Not just appear; they refer to each other getting "old", and at one point Baranski refers to Walters as a "senior citizen". Okay, so maybe Streep's character was impregnated later in life. Nope; repeated dialogue has her in her late teens when she got pregnant. So, to recap: Streep's character, as a young girl in her late teens in the early to mid-sixties, was in a singing group at the time, and met three men, one of whom impregnated her...with a daughter who is still twenty years old in either the late 90s, or (more likely) somewhere around 2008!
    • Bad, but not quite that bad. The problem comes from trying to make a film in 2008 based on a play from 1999, based on music from the late 1970s. The three women were in a group in the 70s, supposed to be based on the Grrl Power movement. It would have been better if they were playing instruments; there were many female singing groups before that, but still a lot of prejudice against women who played their own instruments as seen in The Runaways. As to what Brosnan was wearing, he looked more like a hippie but lots of people identified with and wore clothes from an earlier generation. The problem is the song "Our Last Summer"- it was about 1967 or 1968 (the time of flower power) and released in 1980; it would have fit in perfectly about a young couple in their late thirties talking about their early twenties.
  • In The Man in the Moon, a boy is taking the oldest daughter to a school dance. The dance ends at 11:00, so Dad demands that his daughter be home by 11:30. The problem is that the school is near 30 miles away. That would require going almost 60 mph on back roads. Dad does interrupt the boy's answer with a possible Conjunction Interruption; we don't know what the boy was going to say, but it could have been to note that fact.
  • In Mean Girls Cady is supposed to be a mathematical genius, so the writers used really overcomplicated explanations of how to do simple things like working out percentages, but seem to be okay in terms of accuracy. However, Cady intentionally makes mistakes to help her crush/tutor feel smart, leading to moments like this little exchange:
    Aaron: ...sometimes the product of two negative integers is a positive number.
    Cady: Yeah, like negative four and negative six.
  • Alex O'Connell's age in The Mummy Returns. He's eight in 1933, so he'd have to have been born in 1925. Rick and Evy met in 1926. Neat trick, Alex. The writers for Returns appear to have missed the fact that the first film has a time skip of a couple years between O'Connell's first appearance and him meeting Evey.
  • In Never Been Kissed, the geeky kids sell pies at a bake sale, with a sign proclaiming "pi = 3.1457" followed by some more digits to make it look sufficiently nerdy. Only the first three digits are correct; the rest is nonsense. Also, Josie's initial high school tenure is played against the backdrop of The '80s, when, based on the dates and ages mentioned, they actually should have occurred in 1992, 1991 at the earliest. Instead of the soundtrack you'd expect to hear for a sequence set during the heyday of Grunge, Josie and her classmates are always shown cavorting around to Cyndi Lauper and The Smiths, music more apropos of what should have been their grade school years.
  • In Night at the Museum: Battle of the Smithsonian, an Einstein bobblehead (supposedly as smart as the real Einstein) claims that pi is exactly 3.14159265. Pi is an irrational number, meaning that no matter how many digits you use, you can never get to the exact value.
  • The Odd Couple II is an absolute mess of chronology. The script is never sure how long this film takes place after the original: 30 years (which was the real-time length between the films) or 17 years (because the plot revolves around the marriage of Felix and Oscar's children, neither of whom look much older than 30). The opening caption states "30 years later", but dialogue throughout the next few scenes keep insisting it to be 17 years. And then near the end, Felix and Oscar are confronted with their ex-wives, both of whom they separated from during the events of the first film. Oscar's ex tells him he hasn't changed in 30 years, and then Felix tops it by declaring that he hasn't spoken to his ex in 50 years (!), which would be impossible without their daughter being well into middle-age. What happened, Neil Simon?
  • Ace Attorney: In the present day, Prosecutor Mandred von Karma hasn't lost a case in 40 years. Phoenix says that Gregory Edgeworth found it suspicious that he hadn't lost a case in 40 years... but Gregory was killed 15 years ago, which means von Karma's streak was 25 years at the time.
  • In Roxanne, a modern-day remake of Cyrano de Bergerac, C. D. Bales agrees to make twenty jokes about his own nose. Apparently he and the rest of the bar patrons lost track. He actually did twenty-five jokes. (Word of God says the bar knew and just wanted C.B. to do more insults.)
  • Scanners: Darryl Revok reveals himself to be Cameron Vale's older brother, then tells him that one of them was born in 1943, the other in 1948. Earlier in the film both characters are stated to be thirty-five years old by Dr. Ruth. Either their birth dates are incorrect or one of their ages is.
  • A Serious Man: When Larry scrawls the equations of the uncertainty principle on a chalkboard, he miswrites one of the equations as "Δp = √(<p>^2 - <p>^2)", making the equation the square root of zero (which is zero). The correct equation is "Δp = √(<p^2> - <p>^2)".
  • Played with in Stranger Than Fiction: Harold is asked a complicated math question and can't think because of the narrator in his head. She tells him an answer, which he promptly says out loud. She then says that answer was wrong and gives another one, causing Harold to apologize and switch to the new answer. The first answer was the right one. This was intentional on the part of the writer.
  • Marvel Cinematic Universe:
    • A line in Thor: Ragnarok ("We were eight at the time.") hints that Thor and Loki might have been raised as twins, and the Minor Kidroduction at the beginning of Thor shows them looking the same age (both actors were 11). However, while Thor shows that the battle against the Frost Giants was in 965 (which is also likely Loki's birth year), 1053 years before the events of Avengers: Infinity War, in this film Thor states that he is 1500 years old.
    • The opening scene where Toomes is cleaning up the wreckage from the Battle of New York is stated to take place eight years before the rest of the scenes in Spider-Man: Homecoming. However, this is impossible. The Battle that was shown in The Avengers (2012) occurred in 2012 (as confirmed in Agents of S.H.I.E.L.D.), after the May 2011 Stark Expo (as seen in "Fury's Big Week"). And main events of Homecoming take place in 2016, a few months after Captain America: Civil War, before the second and third acts of Doctor Strange (2016) and before the events of the fourth season of Agents of S.H.I.E.L.D.. In Civil War Vision makes a reference to Tony Stark revealing himself as Iron Man to the world eight years ago, and Iron Man was released in 2008 and has been understood to take place in either 2009 or 2010. To complicate the matter futher, Aaron Davis is mentioned to be 33 years old in Homecoming, and his criminal record states a birth date of April 1984, which would set the rest of the movie in 2017 rather than 2016. The "Eight years later" thing was admitted to be an error.
  • One scene in St. Trinian's had Stephen Fry award points to a team for concluding that the volume of a sphere is πr^3. A fourteen-year-old could probably tell you that it's actually (4πr^3)/3. Clearly the writer extrapolated from πr^2 giving the area of a circle. Although he claimed in his biography to enjoy studying maths under his father, Stephen Fry is much better versed in humanities than mathematics, otherwise he might have spotted this one.
    • The scene has three characters make the same mistake: the contestant (a student at a presumably top school), the bursar (a numbers man), and Stephen Fry. It's...odd, to say the least.
  • At the end of Summer School, the students' final grades in Remedial English are recounted in front of their teacher and two school administrators. Apparently the vice-principal could use some Remedial Math, because the average he cites for the class as a whole (63%) isn't the actual mean of the grades reported (43, 51, 74, 38, 75, 59, 70, 82, 91).
    • He's off by less than two doing very quick math. Fairly good guess, actually.
  • In Super Mario Bros., Spike, after being turned super-intelligent, asks Iggy what the square root of 26,481 is, while delivering the answer immediately: 191. The thing is, 191 is actually the square root of 36,481.
  • Terminator:
    • The Judgment Day was to occur August 1997. John Connor was born February 1985. Terminator 2: Judgment Day shows him at the age of ten being attacked by the Terminator. Terminator 3: Rise of the Machines then Retcons his T2 age to thirteen. The problem is that he wouldn't turn thirteen for six months after the bombs supposedly fell in Kyle Reese's timeline.
    • In the second movie (set in 1995), Dr. Silberman explicitly refers to Sarah as 29 years old. In T3, the gravesite indicates that she was born in 1959, which would have made her 36 in that year, and 24 or 25 in the first movie, where she is stated to be eighteen.
    • Kyle Reese questions a policeman at the beginning of the first film about the date, and gets the response "12th! May! Thursday!" However, that date in 1984 was a Saturday. It would have been the correct weekday in 1983, which was when the film was originally supposed to be made, but it was postponed due to Arnold Schwarzenegger having other commitments.
  • Transformers: Revenge of the Fallen: 5 Decepticons go into the water to revive Megatron. When they get down there, they kill one for parts and revive Megatron. When they go up, a sub commander says that six are going up.
  • The Wizard of Oz: The infamous "Sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side." mangling of the Pythagorean theorem, as said by the scarecrow after he got his brain. It should be, "The square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides." This is lampshaded in The Simpsons, where Homer says the exact same line in an attempt to sound smart after putting on Henry Kissinger's lost glasses, and a person in the bathroom yells out, "That's a right triangle, you idiot!" Homer then responds to this with "D'OH!". The French dub of the film (titled Le Magicien d'Oz) averts the mistake, where the Scarecrow says "La somme de l'hypoténuse au carré doit être égale á la somme des deux cotés opposés au carré", or "The square of the hypotenuse must equal the squares of the two other sides" in English.
  • In X-Men: First Class there is a scene with Charles Xavier as a child which is set in 1944, while the bulk of the story takes place in 1962. However, the two actors are credited as playing "Charles Xavier: 12 years" and "Charles Xavier: 24 years".

  • The song/story "A Billion Baseballs" by the Green Chili Jam Band does multiple calculations related to these baseballs and gets almost all of them wrong. For example, it says that this many baseballs placed on the ground would take up a giant square "eighty miles around." Since baseballs are three-inch diameter objects, a square of 31,623 by 31,623 baseballs would have a perimeter of under six miles.
  • Foxy Brown's verse on The Firm's "Affirmative Action" contains this horrible bit of addition:
    We gotta flee to Panama, but wait it's half-and-half
    Keys is one and two-fifth, so how we flip
    Thirty-two grams raw, chop it in half, get sixteen, double it times three
    We got forty-eight, which mean a whole lot of cream
    Divide the profit by four, subtract it by eight
    We back to sixteen, now add the other two that 'Mega bringin' through
    So let's see, if we flip this other key
    Then that's more for me, mad coke and mad leak
    Plus a five hundred, cut in half is two-fifty
    Now triple that times three, we got three-quarters of another ki
  • The Shooter Jennings concept album "Black Ribbons" is set in a not-too-distant future dystopia. The narrator, the Will 'o the Wisp, makes reference to a real book published in the 1970s, stating it was written forty years ago, putting the date around 2010, when the album was released. This could be a case of a changed past, but then he mentions Obama's election and says everything went to seed after that. Either Obama's term was cut short, or the math is wonky. This is made worse by the fact that Stephen King wrote the narration.
  • The Rage Against the Machine track "Down Rodeo" includes the classic hook: So now I'm rollin down Rodeo with a shotgun / These people ain't seen a brown-skinned man / since their grandparents bought one. Even if the song is describing a 1960s Black Panther, which the lyrics seem to suggest, that's over a century since the end of slavery, making it extremely unlikely that anyone there would have been old enough to see one purchased. That lyric is obviously not meant to be taken literally.
  • "The Doctor's Wife" by The Clockwork Quartet magnificently details an Apocalyptic Log by a doctor obsessed with curing his wife of a serious illness. The only trouble is, the dates at the beginning of each verse conform to no known calendar.
  • In the Vietnam War protest song "I Was Only 19" by Redgum is the line And Frankie kicked a mine the day that mankind kicked the moon / God help him, he was going home in June which implies that Frankie was about to go home when he was killed by a mine. But the moon landing didn't happen until July - which would mean Frankie still had almost an entire year of service to go.

    Myths & Religion 
  • The people of the northern Kingdom of Israel, who were scattered by the Assyrians and disappear from the historical record after that, are popularly known as the "Ten Lost Tribes." The only problem is that the Northern Kingdom consisted of only nine tribes — Reuben, Issachar, Zebulun, Dan, Naphtali, Gad, Asher, Ephraim, and Manasseh. The most likely explanation is that somebody subtracted the two tribes of the Southern Kingdom, Judah and Benjamin, from the traditional twelve without realizing that the tribe of Simeon had disappeared from the census at this point; and the priestly tribe of Levi (which by law had no land holdings) was spread out through both kingdoms. The math was always a bit fuzzy anyway, since Ephraim and Manasseh were actually half-tribes (being descended from Joseph's two sons) and the other tribes would sometimes kick Dan off the list for its wickedness (having slaughtered and resettled in a defenseless town in the book of Judges).
  • In the Christian Bible, a temple includes a sea (large bowl) of "cast metal, circular in shape, measuring ten cubits from rim to rim and five cubits high. It took a line of thirty cubits to measure around it," implying that pi is equal to 3 and not 3.14159. However, the sea is also mentioned as being a "handbreadth" thick. Taking the thickness of the sea into account, the numbers match quite accurately.

    Pro Wrestling 
  • Scott Steiner's infamous promo for a match against Samoa Joe and Kurt Angle in TNAnote :
    -> "You know they say all men are created equal, but you look at me and you look at Samoa Joe and you can see that statement is NOT TRUE! See, normally if you go one-on-one with another wrestler you got a fifty/fifty chance of winning. But I'm a genetic freak, and I'm not normal! So you got a 25 percent at best at beating me! And then you add Kurt Angle to the mix? You-the chances of winning drasticy go down. See, the 3-Way at Sacrifice, you got a 33 and a third chance of winning. But I! I got a 66 and two thirds chance of winning, cuz Kurt Angle KNOOOWS he can't beat me, and he's not even gonna try. So, Samoa Joe, you take your thirty three and a third chance minus my twenty five percent chance (if we was to go one on one) and you got an eight and a third chance of winning at Sacrifice. But then you take my 75 perchance-chance of winnin' (if we was to go one on one), and then add 66 and two thirds…percents, I got a 141 2/3 chance of winning at Sacrifice! Señor Joe? The numbers don't lie, and they spell disaster for you at Sacrifice!"

  • The Phantom of the Opera takes place in 1881. Its sequel, Love Never Dies, takes place ten years later, in 1907. Phantom itself has had its share of chronology issues — the dates of the prologue, the principal action, and the death of Christine's father have shifted several times since the show's inception, and trying to reconcile all three dates with each other has resulted in headaches for many a phan. A brief discussion on the subject can be found here.
  • The Pajama Game has a song named "Seven and a Half Cents" involving the singers detailing what they could buy with that raise over a given number of years. For the last figure for ten years, they forget to carry when multiplying, resulting in the wrong answer.
  • The stage version of Hairspray starts on a Monday in "early June", 1961. It ends on June 6th, 1961. However, around 10 days pass between the beginning and ending scenes. This problem is compounded by the fact that the first Monday in June, 1961, was the 4th.
  • In Fiddler on the Roof after a Time Skip, Tevye says Tzeitel and Motel have been married for two months. A scene or two later (with no time skip), they have a baby. Either Tzeitel had the world's shortest pregnancy or she somehow had no full belly when she was seven months pregnant at her wedding.
  • Charlie and the Chocolate Factory falls afoul of this in Act One with regards to Veruca Salt finding her Golden Ticket. In the "I Am" Song "When Veruca Says" her father claims that his workers were "shelling" Wonka Bars "for forty days and forty nights", but the contest was only announced the previous day. (Granted, it might have felt that way since they're dealing with Veruca Salt here.) This might be a matter of the book and the lyrics being penned by different writers.

  • BIONICLE has this across its multiple forms of media.
    • The size of the Great Spirit Robot was increased from its originally intended height (about a small-to-middle sized continent) to roughly the diameter of Earth without other measurements being changed accordingly. This means the Denmark-sized island that was supposed to be covering the fallen robot's head would't have fit.
    • Practically all forms of media disregard any given measurements when depicting the sizes and population numbers of cities or villages. Depending on which part of the story you're looking at, the population of Metru Nui/Mata Nui can be several thousands, exactly one thousand (plus its small group of leaders and protectors), or just dozens. The online games have an excuse in that they couldn't possibly have programmed that many characters.
    • Water began pouring into Karda Nui through an island-sized hole, which under a thousand years only managed to flood its bottom. While Karda Nui is a gigantic place and its sizes can only be guessed at though comparing different pieces of concept art, fans have calculated that even under the most lenient of circumstances, the place would have been filled with water in a matter of weeks.

    Visual Novels 
  • Narcissu and its sequel, Narcissu ~ Side 2nd, have trouble keeping Setsumi's age straight. In Side 2nd (which takes place during the summer of 1999), Setsumi is referred to as being an Aquaries (thus born in late January or February), and it is alternatively claimed that she is fifteen years old, or that it is her fifteenth summer (which would make her fourteen). The original game (taking place in late January and early February of 2005), claim that she is 22, but adding the years up from her claimed age in Side 2nd indicate that she should be within a month of either her 20th or 21st birthday, depending on whether one uses the "15th Summer" claim or the "15 years old" claim. Also, in the prologue of Side 2nd (which takes place between the two stories), Setsumi makes a remark about how she's been hospitalized on and off for a decade. The main story indicates that she was first hospitalized sometime in April 1997, thus making it impossible for the claim of a decade to be correct.
  • In Higurashi: When They Cry, Hinamizawa has a population of roughly 2000, yet there are only 20 pupils in the village's only school. Realistically, around one tenth of a population would be of school age. (The TIPS say that half the children in the village go to school in Okinomiya instead, which helps a little, but isn't nearly enough.)
  • Early into Super Danganronpa 2, Monokuma reveals that the students lost two years of their memories. If one however factors in all the cumulative time periods, it actually more than likely twice that number.
  • Some times in Ace Attorney don't match.
    • In the final case of Trials and Tribulations it is stated that Phoenix dated "Dollie" for 6 months, when it was actually almost 8 monthsNote . Corrected in later ports.
    • In Apollo Justice onward, most of the Phoenix Wright-era cast are a year younger than they should be, because of the botched handling of a time skip. To explain further, the trial of Shadi Enigmar happened seven years prior to the events of AJ. When calculating character ages, the writers counted from the start of T&T instead of the end of T&T. (Further confusing things, everything still takes place in the year it's supposed to - only the ages are wrong.)
  • Zero Escape trilogy deals with a lot of science and math, both basic and advanced (mostly done by Akane), and most of the time it gets it right, but few mistakes managed to slip in:
    • At one point in Nine Hours, Nine Persons, Nine Doors Seven pulls up a theory that the ship they're on is RMS Gigantic(a real-life ship that was later renamed to HMHS Britannic), to which Santa reacts with "There is no way we're on a boat that's almost 100 years old". Gigantic was finished in 1914 and game takes place in 2027, so if Gigantic still existed it would be over 100 years old.
    • Zero Time Dilemma:
      • If you fail to get the correct code in the pantry, Carlos will say that a 4 digit-code has "hundreds of thousands of possible combinations". No, it doesn't: it has exactly 10,000 combinations. Akane makes a similar mistake in the infirmary when she claims there is over a thousand possible combinations for a 3-digit code when it's exactly one thousand combinations.
      • At one point, Akane says that the probability of getting 3 ones by throwing three dice at once is 1/216 (which is correct) but attempting it three times would give 1/72 chance, which is close but not entirely correct. The probability of getting at least one success with three attempts is 1 minus the probability of failing three times in a row. In this case it's 1-(215/216)^3, or more precisely 139,321/10,077,696, which is slighly lower than 1/72.

    Web Animation 
  • Homestar Runner: In Coach Z's music video "Rap Song", a featured guest singer proclaims, "My name is Tenerence Love, plus my name is Tenerence Love, divided by my name is Tenerence Love, equals my name is Tenerence Love...remainder 3." Depending on how the operations are grouped, the value of "my name is Tenerence Love" could be -1note  or it could not exist at allnote . note  If we let "my name is Tenerence Love"=x, we have (x+x)/x=2=x+(3/x), since "remainder 3" means the undivided portion of the fraction. Rearranging, we get the statement x^2-2x+3=0, and by using the quadratic equation we find the value of "my name is Tenerence Love"=1+sqrt(2)i or 1-sqrt(2)i.note 

    Web Comics 
  • Averted in Schlock Mercenary here. The author even accounted for the equal amount of regular matter that would be converted to energy when taking 320 milligrams of anti-matter and converting to the equivalent explosion powered by TNT. (Quick link to the maths). Schlock's readers can do math as well: the writer infamously challenged them to, given a few distantly related numbers, calculate the height of the "Hellavator" lunar space elevator, only for several readers to send in accurate calculations and numbers, and show their work.
  • Angel Moxie: In-universe example. Grant accidentally fakes his birthdate as 1971, but the date of his teaching degree as 1983. Luckily, the only ones who notice are the heroines.

    Web Original 
  • The Creepypasta story The Russian Sleep Experiment starts out with five Nazi prisoners and has three by the time they leave the facility, yet still manages to include death scenes for four or five after that.

    Web Videos 
  • The Nostalgia Critic, in his End of Days review, as part of a long string of math equations, infamously uttered that "9+9+9=21". That's about as basic of mathematics as one can get and he screwed it up. He later apologized for it in one of his "Fuck ups" specials.
  • Mario Party TV: One comment pointed out that Steeler miscalculated the odds during the Pagoda Peak playthrough. The probability of rolling 4 of the same number is not 1/10,000. Since the dice blocks are numbered one to five, and there are 5 possible ways to get all 4 numbers being the same, the probability ends up being: 5/(5^4) = 1/125 (about the same as a golden with 1-10 blocks)

"80% of you have no understanding of percentages!"
"We aren't even that many..."

Alternative Title(s): Writers Cannot Do Maths, You Fail Mathematics Forever