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Cake day: July 26th, 2023

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  • Mistic@lemmy.worldtoLemmy Shitpost@lemmy.worldSBA #119 maths
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    23 days ago

    Let me just, ahem

    1-2+3/(3+3)×2+3×6/3 = 1-2+3/(3+3)×2+1×6 = 1-2+3/(3+3)×2+6 = 7-2+3/(3+3)×2 = 7-2+3/(6+6) = 7-2+(1/2+1/2) = 5+(1/2+1/2) = 5+1=6

    Ahh, yes, DMAMDSBA :P

    Let’s just say BODMAS/PEMDAS isn’t all end-all be-all. They’re good, but there’s also better

    For those interested, see: basic number properties


  • 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

    It’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

    Edit: Look, this one even warns you about the implicit multiplication1000061536


  • Mistic@lemmy.worldtoLemmy Shitpost@lemmy.worldSBA #119 maths
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    23 days ago

    Usually, no sign before the bracket means juxtaposition. Scientific calculators do account for it (not all, tho), while regular ones may not.

    So 2(1+2) is really (2+4)

    Compare 2/2x and 2/2×X where x is (1+2)

    The first is 2/(2+4)=1/3, the second is (2/2)×(1+2)=3

    Basically, either 1 or 9 can be considered correct. And yes, it’s ambiguous.

    Also, there’s no real rule about solving left to right due to associative and commutative properties: 1×2×3 = 1×(2×3) = (1×2)×3 = 3×1×2 = 2×1×3 = 6