Wrong vs. Weird, But Not Wrong
Side-by-side examples of algebra that's simply wrong versus algebra that's correct but bizarrely unsimplified, like 13/23 = 0.6500/1.1500 or the redundant x > 3 and x > 2.
Transcript
WRONG ("No. Just no."): 2b = 2 + b + c · 13/23 = 1/2 (by crossing out the 3s) · x > 3 and x < 2
WEIRD, BUT NOT WRONG ("Okay… but why?"): 2bc = bc + cb · 13/23 = 0.6500/1.1500 · x > 3 and x > 2
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Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.
Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2021-06-07-wrong-vs-weird-but-not-wrong/ (CC BY-NC 4.0)