“six-seven” has taken over elementary and middle schools in America. It’s everywhere.
Here’s a clip from a recent south park episode with six-seven.
And here’s a recent xkcd:

And here’s a six-seven character from Roblox:

Be thankful if you aren’t around kids constantly shouting “six-seven!” at each other and laughing.



I’m glad 6 and 7 are on good terms now. Their relationship was rather fraught for a while after the whole cannibalism thing with 7 and 9.
7 is a 6 offender. Be warned.