Why do people keep getting this wrong‽
Stand-up Maths1 HN recommender · recommended in 1 month, 2020–2025
explainer · general · evergreen · 2020–2025 on HN
Matt Parker of Stand-up Maths explains why people keep making the same mistake with millions and billions, using a Bloomberg cash calculator example. He looks at the unit slip behind the repeated arithmetic error.
HN links it to explain why people repeatedly get large-number arithmetic wrong in discussions of money and mental math.
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4 comments from Hacker News
This mistake is so interesting to me. Here's a great explanation of what's probably happening: ▶ this video tl;dr: mentally we take off "millions" as a unit, do the calculation, then add "millions" back on. This works for addition, subtraction, and inequality but fails for multiplication and division.
Reminds me of this classic: link “Bloomberg spent $500 million on ads. The U.S. population is 327 million. He could have given each American $1 million and still have money left over.” ▶ this video
I'm not sure that there's a name for that kind of maths error, but there is a reason why people keep making it, as Matt Parker discusses: ▶ this video .
Matt Parker made a video that tries to explain how people keep getting this basic arithmetic completely wrong. ▶ this video