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Comment on SBA #119 maths

panda_abyss@lemmy.ca ⁨2⁩ ⁨weeks⁩ ago

It’s ambiguous either this resolves to 6 / (2(1+2)) or (6/2) * (1+2), and therefore both answers must be accepted.

By convention, the division sign is not to be used in equations. It is not a standard operation.

It is may be used for representing the operation of division as a symbol, but never as an operator itself.

Anyone using the division sign is using it entirely for trolling purposes.

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FishFace@piefed.social ⁨2⁩ ⁨weeks⁩ ago
This is not true. It typically falls out of use in high school and rarely shows up after, but it’s not like it’s banned or anything like that.

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- panda_abyss@lemmy.ca ⁨2⁩ ⁨weeks⁩ ago
  It’s not in the modern standard for notation. I never once saw it used in university. I even had prof who typed their homework on a typewriter and he didn’t use it (he actually typeset everything pretty nicely).
  
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  - FishFace@piefed.social ⁨2⁩ ⁨weeks⁩ ago
    I think of you looked hard you’d find it :) And it’s even easier to find / used to indicate division which has all the same issues.
    
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0ops@piefed.zip ⁨2⁩ ⁨weeks⁩ ago
I wouldn’t say that it’s ambiguous, you’ll only get one answer evaluating in PE(M|D)(A|S) order left to right (your second one), enter it into any calculator and you should get 9.

For sure, how it’s written is unconventional and easy to misread if I’m in a hurry, but honestly that’s an issue of misleading typography, not ambiguous notation. The ÷ symbol takes a lot of space (plus it looks sort of like a +) and the implicit multiplication against the parentheses doesn’t, so when I read too fast my brain might instinctively calculate each side of the division first because they sort of look like two terms. But doing that violates the left-to-right rule.

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- Mistic@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
  
  enter it into any calculator and you should get 9
  
  Have you tried it, though? My Casio says it’s 1
  
  That’s because it treats 2(1+2) as 2x and not 2*x
  
  That’s called juxtaposition and is the reason why people find this notation ambiguous. Some people account for it, some not. Same with calculators. The scientific ones are most likely to give you an answer of 1
  
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Hiro8811@lemmy.world ⁨2⁩ ⁨weeks⁩ ago
Huh why would you add additional brackets? It’s simply 6:2*(1+2) then you solve it in order since division and multiplication are same level of operation.

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