HackerTube

Why do people keep getting this wrong‽

Stand-up Maths1 HN recommenders · 2020–2025
2M views · explainer · evergreen · Uploaded 2020-03-24

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.

Recreational & visual mathMath & theory (other)

Watch on YouTube

4 comments from Hacker News

@infogulch2020 · in “Fed should pay every American, let hedge funds and billionaires ‘get wiped out’”

Matt Parker made a video that tries to explain how people keep getting this basic arithmetic completely wrong. [VIDEO]

CitesView on HN
@christiangenco2022 · in “What use is mental math in 2022?”

This mistake is so interesting to me. Here's a great explanation of what's probably happening: [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.

RecommendsView on HN
@TRiG_Ireland2023 · in “Edinburgh couple are handed £17K bill by Tesla as they 'drove in rain'”

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: [VIDEO] .

CitesView on HN
@csours2025 · in “Very Wrong Math”

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.” [VIDEO]

CitesView on HN