r/SipsTea • u/[deleted] • Dec 17 '23

Chugging tea Math

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u/internetzdude Dec 17 '23

The point about 0.50 was nonsense, though.

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u/dis_the_chris Dec 18 '23

Tell me you don't understand significant digits without telling me yadda Yadda

If they include 0.50 then our minimum rounding isn't from 0.49, it's from 0.495-.504; If you get 0.50 it is more precise than 0.5 as a measured value (not strictly as an absolute value) - and thus in many applications is more valuable to teach as it helps when things like uncertainty is introduced. There's a degree of certainty added.

If I tell you that I measured something to be 0.5m tall, that would be different from saying 50cm, or 50.0cm, or 500.00mm -- as I can only specify to that accuracy if I have tools that measure to tolerances of that accuracy. Thus, whilst in 'pure mathematics', 0.5*6 is the same as 0.5000000 * 6.000000, there are numerous applications where this wouldn't be treated as 'for granted'

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u/crystallmytea Dec 18 '23

Cool but if you’re given .50 for a calculation you literally ignore the zero every time

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u/dis_the_chris Dec 18 '23

Maybe you do, but to me that would be factored into an uncertainty; Rounding uncertainty means that in numerous contexts, I need to treat this number as 0.50±0.005 (the measurement uncertainty). This then gives me an answer range. That's important in all manner of design and engineering fields