Multiplication Is Not Just Repeated Addition
A sign claiming multiplication is just repeated addition is graffitied with i × i = −1 as a counterexample.
Drawn for Art of Problem Solving (AoPS).
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Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2021-05-01-multiplication-is-not-just-repeated-addition/ (CC BY-NC 4.0)Transcript
[Sign] "MULTIPLICATION IS JUST REPEATED ADDITION" with graffiti: "not" inserted and "then how come i * i = −1"
A: "I want that nasty graffiti cleaned up!" B: "But… what if the graffiti has a point?"