My students are obsessed with the number 21. Whenever I mention it, a chorus of twelve-year-old voices rings out, “Twenny wan.”
Sometimes I’ll ask them if they have any questions. Without fail, they’ll say, “What’s 9 + 10?” and they expect the answer to be 21.
Why? This is not because I am a failure of a math teacher. They say so because of the following vine:
Every day. Twenny wan.
They doodle it all over their quizzes and tests: 9 + 10 = 21.
It’s on their notes: 9 + 10 = 21.
They sneak in and write it on the board: 9 + 10 = 21.