Does 0.4999... Round Up or Down? The Truth About Infinite Decimals ๐ข
Discover how to round 0.4999... and why it's considered closer to 0.5. Learn the math behind infinite decimals and rounding rules in this clear explanation!

Wrath of Math
287.9K views โข Jul 12, 2025

About this video
Pretty much everyone knows that 0.999... = 1, and certainly, even if you argue about that - you might concede that if we were to round 0.999... it would round to 1. But what about 0.4999...? Does this round to 0 or to 1? Today we answer this question by exploring rounding conventions and discussing why 0.4999... is 0.5 in the first place. This question comes from r/askmath. #maths #reddit
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SOURCES
https://www.reddit.com/r/askmath/comments/1lukdbz/when_rounding_to_the_nearest_whole_number_does/
https://en.wikipedia.org/wiki/Rounding
0:00 Intro
1:00 Floor and Ceiling
2:12 The Nearest Whole
5:01 Why Round Up?
9:04 Banker's Rounding
11:51 Mathshion
12:28 Why 0.4999...=0.5
16:58 Final Question
18:04 "Mathematically"
18:52 Conclusion
Check out the coolest math clothes in the world: https://mathshion.com/
Join Wrath of Math to get exclusive videos, lecture notes, and more:
https://www.youtube.com/channel/UCyEKvaxi8mt9FMc62MHcliw/join
More Math Chats: https://www.youtube.com/playlist?list=PLztBpqftvzxXQDmPmSOwXSU9vOHgty1RO
Outro music: https://youtube.com/shorts/tfifiSdTZRg
Follow Wrath of Math on...
โ Instagram: https://www.instagram.com/wrathofmathedu
โ TikTok: https://www.tiktok.com/@wrathofmathedu
โ X: https://x.com/wrathofmathedu
SOURCES
https://www.reddit.com/r/askmath/comments/1lukdbz/when_rounding_to_the_nearest_whole_number_does/
https://en.wikipedia.org/wiki/Rounding
0:00 Intro
1:00 Floor and Ceiling
2:12 The Nearest Whole
5:01 Why Round Up?
9:04 Banker's Rounding
11:51 Mathshion
12:28 Why 0.4999...=0.5
16:58 Final Question
18:04 "Mathematically"
18:52 Conclusion
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Video Information
Views
287.9K
Likes
8.3K
Duration
19:53
Published
Jul 12, 2025
User Reviews
4.7
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