9 10 21

2013Video / Catchphraseclassic

Also known as: What's Nine Plus Ten · 21 Kid · 21 Meme · 9/10/21

9 + 10 = 21 is a 2013 Vine video meme featuring a young boy confidently answering "What's 9 + 10?" with the incorrect punchline "21.

"9 + 10 = 21" is a viral meme originating from a 2013 Vine video in which a young boy confidently answers the math problem "What's 9 + 10?" with "21" instead of the correct answer, 191. The clip spread rapidly through Vine remixes, YouTube compilations, and music mashups before experiencing a massive resurgence in September 2021, when the calendar date 9/10/21 aligned with the meme's punchline3. It's one of the most iconic Vine-era memes and a staple of early 2010s internet humor.

TL;DR

"9 + 10 = 21" is a viral meme originating from a 2013 Vine video in which a young boy confidently answers the math problem "What's 9 + 10?" with "21" instead of the correct answer, 19.

Overview

The meme centers on a short Vine clip where an off-camera person tells a young boy "you stupid." When the boy protests, he's asked to prove otherwise by solving a basic math problem: "What's 9 + 10?" The boy answers "21" with complete confidence, prompting the questioner to repeat: "You stupid"4. The humor comes from the kid's unshakable certainty in his wrong answer and the blunt punchline2. The audio clip, the phrase "21," and still frames from the video all became independently memeable, spreading far beyond Vine to become a universal internet joke about getting something obviously wrong5.

The original Vine was uploaded on June 22, 2013, by users @DREHUPEMSU and @WESTROSECRAN1. The short clip featured what appears to be an older person filming a younger boy, asking him the simple math question. Within its lifetime on Vine, the post pulled in over 30 million loops, 707,000 likes, and 605,000 revines4. The child in the video, whose real identity was never publicly confirmed, became known online simply as "The 21 Kid"4. The raw, unpolished quality of the clip gave it a feeling of genuine candid humor rather than a scripted skit2.

Origin & Background

Platform
Vine
Creator
@DREHUPEMSU / @WESTROSECRAN
Date
2013
Year
2013

The original Vine was uploaded on June 22, 2013, by users @DREHUPEMSU and @WESTROSECRAN. The short clip featured what appears to be an older person filming a younger boy, asking him the simple math question. Within its lifetime on Vine, the post pulled in over 30 million loops, 707,000 likes, and 605,000 revines. The child in the video, whose real identity was never publicly confirmed, became known online simply as "The 21 Kid". The raw, unpolished quality of the clip gave it a feeling of genuine candid humor rather than a scripted skit.

How It Spread

The first notable remix on Vine came from user BRUH, which racked up over 7.14 million loops, 185,000 likes, and 145,000 revines. The soundbite "21" became a standalone punchline within the Vine community, dropped into countless other skits as the answer to any question.

After the original Vine was deleted, the video was re-uploaded to YouTube on July 7, 2014, by Alondra Morelos, and again on July 9 by YouTuber Shadow Subscribe. By December 2014, those uploads had collected 5.7 million and 3.7 million views respectively. On August 29, 2014, YouTube user SwiftStar352 uploaded a trap remix blending the "21" audio with Bobby Shmurda's hit "Hot Nigga," which reached 14.6 million views before being taken down.

On October 13, 2014, the parody site Huzlers published a fake article claiming "The 21 Kid" had gone missing, complete with a fabricated goodbye note. The hoax fooled enough people that discussions popped up on message boards like IGN. The original Vine poster responded with a video featuring a photo of the kid, confirming he was fine. Years later, on October 3, 2020, YouTuber WavyWebSurf posted a deep-dive into the hoax that pulled over 3.7 million views.

The meme saw a major resurgence in summer 2019, with new edits flooding Twitter, iFunny, and Instagram. On April 4, 2019, a "Not Funny, Didn't Laugh" edit using a still from the Vine was uploaded to YouTube. On July 1, Twitter user @Timotainment posted a version featuring Donkey Kong, gaining over 413,000 views and 46,100 likes in a month.

How to Use This Meme

The meme typically works in a few ways:

1

The audio drop: Use the "21" soundbite as a punchline in video edits. Someone asks a question with an obvious answer, and the clip plays "21" instead.

2

The text format: Post "9 + 10 = 21" or just "21" as a response to someone getting something obviously wrong. It signals confident incorrectness.

3

The reaction image: Use a still frame of the kid from the Vine as a reaction to bad math, flawed logic, or anyone being wrong with total conviction.

4

The calendar reference: On September 10 of any year ending in 21, post memes linking the date to the original clip.

Cultural Impact

The meme broke out of internet spaces in several ways. The September 10, 2021, "Judgement Day" event turned a single Vine clip into a coordinated internet holiday, with the hashtag #nineten21 trending on Twitter and meme pages across platforms participating in synchronized celebrations. The meme is frequently cited as one of the defining clips of the Vine era, alongside "Why you always lyin'" and "Do it for the Vine".

The 2020 WavyWebSurf video investigating the Huzlers hoax introduced the meme's backstory to a YouTube audience years after Vine's shutdown, collecting over 3.7 million views. The meme is popular especially within the gaming community and among Millennials and Gen Z audiences between ages 12 and 30.

Full History

The clip's earliest life was contained entirely within Vine's ecosystem, where the "revine" feature and easy audio reuse helped it spread fast. Users treated "21" as a universal wrong answer, inserting it into every conceivable setup. As Vine's influence waned, "Best of Vine" compilations on YouTube carried the meme to a much wider audience who had never used the original app. This cross-platform migration was critical to the meme's longevity.

The Bobby Shmurda trap remix in August 2014 marked a turning point. Musical remixes on YouTube and SoundCloud gave the meme a second dimension beyond the original video format. The audio became detachable from the visual, showing up in contexts where people had never seen the original Vine.

The Huzlers hoax in October 2014 created genuine panic among fans of the clip. Posts on IGN forums and other message boards showed that many users believed the kid had actually run away. The original poster's reassurance video, uploaded to his own Vine page, was later verified by WavyWebSurf as authentic. This incident showed how deeply the "21 Kid" had embedded himself in internet culture, and how protective the community felt toward the child behind the joke.

After a quieter period in the mid-2010s, 2019 brought a second wave. Multiple notable edits appeared across Twitter, iFunny, and Instagram between April and July 2019, including versions by @Zenkho_, @TunnelingOG, and professionalretard.mp4. The meme had evolved from its Vine origins into something platform-agnostic and endlessly remixable.

The biggest moment came in 2021. In January, a Twitter account called @twentyonecount launched with a single purpose: counting down the days until September 10, 2021, the date when "9 + 10 really equals 21". The account posted daily countdown tweets and built a following of over 98,000 by early September. On August 23, @twentyonecount posted a screenshot from the original video with the caption "When the day comes, on 9/10/21, he will decide your fate," earning over 80,000 likes.

As September 10 approached, meme accounts across Instagram and Twitter ramped up the hype. Instagram page @spoobydoo posted an image of the 21 Kid looming over a cityscape with the text "9/10/21 Judgement Day," pulling 46,000 likes. The joke framed the date as an apocalyptic event, with users calling it "Judgement Day" and claiming the world might end. UK users joked they were safe since the British date format reads 10/9/21, which doesn't match the meme.

At midnight on September 10, @twentyonecount posted "TODAY IS 9/10/21" alongside a video edit that gained over 110,000 likes and 32,000 retweets within a day. The hashtag #nineten21 trended on Twitter. Meme accounts celebrated with tribute videos: Instagram pages @salad.snake and @repostrandy posted edits that collectively hit over 239,000 views in under 11 hours. Many users changed their profile pictures to the 21 Kid for the day.

The September 10, 2021, event proved something unusual about this meme. Most Vine-era content faded when the platform shut down in 2017. The "21" meme not only survived but generated a culturally significant moment years later, driven entirely by the coincidence of a calendar date lining up with a wrong math answer. The meme's audio also found its way onto TikTok, where a new generation of users encountered it through trap remixes and sound trends.

Fun Facts

The Huzlers hoax article about the "21 Kid" going missing in October 2014 was convincing enough to spark real concern on gaming forums like IGN.

UK users joked on September 10, 2021, that they were safe from "Judgement Day" because the British date format (10/9/21) doesn't match the meme.

The original Vine was deleted at some point, but the audio and video lived on through YouTube re-uploads and Vine compilations.

On September 10, 2021, many social media users changed their profile pictures to the 21 Kid as a coordinated tribute.

The meme's audio crossed at least four major platforms in its lifetime: Vine, YouTube, Twitter/Instagram, and TikTok.

Derivatives & Variations

Trap remixes

The SwiftStar352 mashup with Bobby Shmurda's "Hot Nigga" was the most viral, hitting 14.6 million views. SoundCloud producers created dozens of additional remixes[4].

"Not Funny, Didn't Laugh" edits

Multiple creators paired the 21 Kid still with the "Not Funny" format, including @Timotainment's Donkey Kong version (413,000+ views)[4].

@twentyonecount

A dedicated Twitter countdown account that ran from January to September 2021, becoming a meme event organizer with 98,000+ followers[4].

"Judgement Day" imagery

Instagram creators like @spoobydoo made apocalyptic edits featuring the 21 Kid towering over cityscapes[4].

TikTok audio remixes

The clip's audio became a reusable sound on TikTok for a new generation of users unfamiliar with the original Vine[2].

Frequently Asked Questions

9 10 21

2013Video / Catchphraseclassic

Also known as: What's Nine Plus Ten · 21 Kid · 21 Meme · 9/10/21

9 + 10 = 21 is a 2013 Vine video meme featuring a young boy confidently answering "What's 9 + 10?" with the incorrect punchline "21.

"9 + 10 = 21" is a viral meme originating from a 2013 Vine video in which a young boy confidently answers the math problem "What's 9 + 10?" with "21" instead of the correct answer, 19. The clip spread rapidly through Vine remixes, YouTube compilations, and music mashups before experiencing a massive resurgence in September 2021, when the calendar date 9/10/21 aligned with the meme's punchline. It's one of the most iconic Vine-era memes and a staple of early 2010s internet humor.

TL;DR

"9 + 10 = 21" is a viral meme originating from a 2013 Vine video in which a young boy confidently answers the math problem "What's 9 + 10?" with "21" instead of the correct answer, 19.

Overview

The meme centers on a short Vine clip where an off-camera person tells a young boy "you stupid." When the boy protests, he's asked to prove otherwise by solving a basic math problem: "What's 9 + 10?" The boy answers "21" with complete confidence, prompting the questioner to repeat: "You stupid". The humor comes from the kid's unshakable certainty in his wrong answer and the blunt punchline. The audio clip, the phrase "21," and still frames from the video all became independently memeable, spreading far beyond Vine to become a universal internet joke about getting something obviously wrong.

The original Vine was uploaded on June 22, 2013, by users @DREHUPEMSU and @WESTROSECRAN. The short clip featured what appears to be an older person filming a younger boy, asking him the simple math question. Within its lifetime on Vine, the post pulled in over 30 million loops, 707,000 likes, and 605,000 revines. The child in the video, whose real identity was never publicly confirmed, became known online simply as "The 21 Kid". The raw, unpolished quality of the clip gave it a feeling of genuine candid humor rather than a scripted skit.

Origin & Background

Platform
Vine
Creator
@DREHUPEMSU / @WESTROSECRAN
Date
2013
Year
2013

The original Vine was uploaded on June 22, 2013, by users @DREHUPEMSU and @WESTROSECRAN. The short clip featured what appears to be an older person filming a younger boy, asking him the simple math question. Within its lifetime on Vine, the post pulled in over 30 million loops, 707,000 likes, and 605,000 revines. The child in the video, whose real identity was never publicly confirmed, became known online simply as "The 21 Kid". The raw, unpolished quality of the clip gave it a feeling of genuine candid humor rather than a scripted skit.

How It Spread

The first notable remix on Vine came from user BRUH, which racked up over 7.14 million loops, 185,000 likes, and 145,000 revines. The soundbite "21" became a standalone punchline within the Vine community, dropped into countless other skits as the answer to any question.

After the original Vine was deleted, the video was re-uploaded to YouTube on July 7, 2014, by Alondra Morelos, and again on July 9 by YouTuber Shadow Subscribe. By December 2014, those uploads had collected 5.7 million and 3.7 million views respectively. On August 29, 2014, YouTube user SwiftStar352 uploaded a trap remix blending the "21" audio with Bobby Shmurda's hit "Hot Nigga," which reached 14.6 million views before being taken down.

On October 13, 2014, the parody site Huzlers published a fake article claiming "The 21 Kid" had gone missing, complete with a fabricated goodbye note. The hoax fooled enough people that discussions popped up on message boards like IGN. The original Vine poster responded with a video featuring a photo of the kid, confirming he was fine. Years later, on October 3, 2020, YouTuber WavyWebSurf posted a deep-dive into the hoax that pulled over 3.7 million views.

The meme saw a major resurgence in summer 2019, with new edits flooding Twitter, iFunny, and Instagram. On April 4, 2019, a "Not Funny, Didn't Laugh" edit using a still from the Vine was uploaded to YouTube. On July 1, Twitter user @Timotainment posted a version featuring Donkey Kong, gaining over 413,000 views and 46,100 likes in a month.

How to Use This Meme

The meme typically works in a few ways:

1

The audio drop: Use the "21" soundbite as a punchline in video edits. Someone asks a question with an obvious answer, and the clip plays "21" instead.

2

The text format: Post "9 + 10 = 21" or just "21" as a response to someone getting something obviously wrong. It signals confident incorrectness.

3

The reaction image: Use a still frame of the kid from the Vine as a reaction to bad math, flawed logic, or anyone being wrong with total conviction.

4

The calendar reference: On September 10 of any year ending in 21, post memes linking the date to the original clip.

Cultural Impact

The meme broke out of internet spaces in several ways. The September 10, 2021, "Judgement Day" event turned a single Vine clip into a coordinated internet holiday, with the hashtag #nineten21 trending on Twitter and meme pages across platforms participating in synchronized celebrations. The meme is frequently cited as one of the defining clips of the Vine era, alongside "Why you always lyin'" and "Do it for the Vine".

The 2020 WavyWebSurf video investigating the Huzlers hoax introduced the meme's backstory to a YouTube audience years after Vine's shutdown, collecting over 3.7 million views. The meme is popular especially within the gaming community and among Millennials and Gen Z audiences between ages 12 and 30.

Full History

The clip's earliest life was contained entirely within Vine's ecosystem, where the "revine" feature and easy audio reuse helped it spread fast. Users treated "21" as a universal wrong answer, inserting it into every conceivable setup. As Vine's influence waned, "Best of Vine" compilations on YouTube carried the meme to a much wider audience who had never used the original app. This cross-platform migration was critical to the meme's longevity.

The Bobby Shmurda trap remix in August 2014 marked a turning point. Musical remixes on YouTube and SoundCloud gave the meme a second dimension beyond the original video format. The audio became detachable from the visual, showing up in contexts where people had never seen the original Vine.

The Huzlers hoax in October 2014 created genuine panic among fans of the clip. Posts on IGN forums and other message boards showed that many users believed the kid had actually run away. The original poster's reassurance video, uploaded to his own Vine page, was later verified by WavyWebSurf as authentic. This incident showed how deeply the "21 Kid" had embedded himself in internet culture, and how protective the community felt toward the child behind the joke.

After a quieter period in the mid-2010s, 2019 brought a second wave. Multiple notable edits appeared across Twitter, iFunny, and Instagram between April and July 2019, including versions by @Zenkho_, @TunnelingOG, and professionalretard.mp4. The meme had evolved from its Vine origins into something platform-agnostic and endlessly remixable.

The biggest moment came in 2021. In January, a Twitter account called @twentyonecount launched with a single purpose: counting down the days until September 10, 2021, the date when "9 + 10 really equals 21". The account posted daily countdown tweets and built a following of over 98,000 by early September. On August 23, @twentyonecount posted a screenshot from the original video with the caption "When the day comes, on 9/10/21, he will decide your fate," earning over 80,000 likes.

As September 10 approached, meme accounts across Instagram and Twitter ramped up the hype. Instagram page @spoobydoo posted an image of the 21 Kid looming over a cityscape with the text "9/10/21 Judgement Day," pulling 46,000 likes. The joke framed the date as an apocalyptic event, with users calling it "Judgement Day" and claiming the world might end. UK users joked they were safe since the British date format reads 10/9/21, which doesn't match the meme.

At midnight on September 10, @twentyonecount posted "TODAY IS 9/10/21" alongside a video edit that gained over 110,000 likes and 32,000 retweets within a day. The hashtag #nineten21 trended on Twitter. Meme accounts celebrated with tribute videos: Instagram pages @salad.snake and @repostrandy posted edits that collectively hit over 239,000 views in under 11 hours. Many users changed their profile pictures to the 21 Kid for the day.

The September 10, 2021, event proved something unusual about this meme. Most Vine-era content faded when the platform shut down in 2017. The "21" meme not only survived but generated a culturally significant moment years later, driven entirely by the coincidence of a calendar date lining up with a wrong math answer. The meme's audio also found its way onto TikTok, where a new generation of users encountered it through trap remixes and sound trends.

Fun Facts

The Huzlers hoax article about the "21 Kid" going missing in October 2014 was convincing enough to spark real concern on gaming forums like IGN.

UK users joked on September 10, 2021, that they were safe from "Judgement Day" because the British date format (10/9/21) doesn't match the meme.

The original Vine was deleted at some point, but the audio and video lived on through YouTube re-uploads and Vine compilations.

On September 10, 2021, many social media users changed their profile pictures to the 21 Kid as a coordinated tribute.

The meme's audio crossed at least four major platforms in its lifetime: Vine, YouTube, Twitter/Instagram, and TikTok.

Derivatives & Variations

Trap remixes

The SwiftStar352 mashup with Bobby Shmurda's "Hot Nigga" was the most viral, hitting 14.6 million views. SoundCloud producers created dozens of additional remixes[4].

"Not Funny, Didn't Laugh" edits

Multiple creators paired the 21 Kid still with the "Not Funny" format, including @Timotainment's Donkey Kong version (413,000+ views)[4].

@twentyonecount

A dedicated Twitter countdown account that ran from January to September 2021, becoming a meme event organizer with 98,000+ followers[4].

"Judgement Day" imagery

Instagram creators like @spoobydoo made apocalyptic edits featuring the 21 Kid towering over cityscapes[4].

TikTok audio remixes

The clip's audio became a reusable sound on TikTok for a new generation of users unfamiliar with the original Vine[2].

Frequently Asked Questions