• DefederateLemmyMl@feddit.nl
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    5 hours ago

    If you have a bunch of unparenthesized addition and subtraction, left to right is correct

    If you have a bunch of unparenthesized addition and subtraction, left to right doesn’t matter.

    1 + 2 + 3 = 3 + 2 + 1

    • MotoAsh@piefed.social
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      6 hours ago

      True, but as with many things, something has to be the rule for processing it. For many teachers as I’ve heard, order of appearance is ‘the rule’ when commutative properties apply. … at least until algebra demands simplification, but that’s a different topic.

        • Quatlicopatlix@feddit.org
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          3 hours ago

          Yes thank you! If you have a sum it is really great to order it in a way that makes it better to ad in your head and i think that lots of people do that without thinking about it. X=2+3+1+6+2+4+7+5 X=2+3+5+4+6+7+1+2 X=5+5 + 10 +7+1+2 X=10 + 10 + 7+3 X=10 + 10 + 10

        • MotoAsh@piefed.social
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          3 hours ago

          No, you completely misunderstood my point. My point is not to describe all valid interpretations of the commutative property, but the one most slow kids will hear.

          OFC the actual rule is the order doesn’t matter, but kids that don’t pick up on the nuance of the commutative property will still remember, “order of appearance is fine”.