9 / 10 123movies133... | Ultra HD

original sound - soundeffectpack ... Stupid? No, not. What's 9 + 10? 21, you stupid. TikTok·althea420

The story began in 2013 with a short, six-second video that captured a simple yet hilariously confident mistake. In the clip, an older brother is recording his younger brother, who would eventually be known across the internet as the "21 Kid". 9 / 10 123movies133...

: People created absurd logical loops to "prove" the kid was actually a genius and that 9 + 10 really does equal 21. original sound - soundeffectpack

: It is still frequently referenced today whenever someone makes a glaringly obvious math error. What's 9 + 10

The "9 / 10 123movies..." part of your query likely refers to how people search for or title these classic meme clips on free streaming or video-sharing sites where these "internet relics" are archived. What's 9 Plus 10? The Meme Explained - TikTok