SmartmanApps comments on A fake Facebook event disguised as a math problem has been one of its top posts for 6 months

[–] SmartmanApps@programming.dev -1 points 1 year ago (4 children)

they aren’t teaching math.

Yes we are. Adults forgetting it is another matter altogether.

There’s no such thing as “order of operations” in math

Yes there is! 😂

Do you think I’m wrong?

No, I know you're wrong.

If so, why?

If you don't solve binary operators before unary operators you get wrong answers. 2+3x4=14, not 20. 3x4=3+3+3+3 by definition

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[–] Mistic@lemmy.world 0 points 1 year ago* (last edited 1 year ago) (3 children)

Yes we are

Yes and no. You teach how to solve equations, but not the fundamentals (and if you do then kudos to you, as it's not a trivial accomplishment). Fundamentals, most of the time, are taught in universities. It's so much easier that way, but doesn't mean it's right. People call it math, which is fair enough, but it's not really math in a sense that you don't understand the underlying principles.

Yes there is!

Nope.

There's only commutation, association, distribution, and identity. It doesn't matter in which order you apply any of those properties, the result will stay correct.

2×2×(2-1)/2 = 2×(4-2)/2 = 1×(4-2) = 4-2 = 2

As you can see, I didn't follow any particular order and still got the correct result. Because no basic principle was broken.

Or I could also go

2×2×(2-1)/2 = 4×(2-1)/2 = 4×(1-0.5) = 4×0.5 = 2

Same result. Completely different order, yet still correct.

My response to the rest goes back to the aforementioned.

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[–] SmartmanApps@programming.dev 0 points 1 year ago (2 children)

You teach how to solve equations, but not the fundamentals

Nope. We teach the fundamentals. Adults not remembering them doesn't mean they weren't taught. Just pick up a Maths textbook. It's all in there. Always has been.

Fundamentals, most of the time, are taught in universities

No they're not. They only teach order of operations from a remedial point of view. Most of them forget about The Distributive Law. I've seen multiple Professors be told by their students that they were wrong.

it’s not really math in a sense that you don’t understand the underlying principles

The Constructivist learners have no trouble at all understanding it.

Nope.

Yep!

There’s only commutation, association, distribution, and identity.

And many proofs of other rules, which you've decided to omit mentioning.

It doesn’t matter in which order you apply any of those properties, the result will stay correct

But the order you apply the operations does matter, hence the proven rules to be followed.

2×2×(2-2)/2

Notably you picked an example that has no addition, subtraction, or distribution in it. That's called cherry-picking.

Completely different order, yet still correct

Yep, because you cherry-picked a simple example where it doesn't matter. It's never going to matter when you only pick operations which have the same precedence.

My response to the rest goes back to the aforementioned

...cherry-picking.

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[–] Mistic@lemmy.world 0 points 1 year ago* (1 child)

We teach the fundamentals

Sure. They are, however, not the focus. At least that's not how I've been taught in school. You're not teaching kids how to prove the quadratic formula, do you? No, you teach them how to use it instead. The goal here is different.

They only teach order of operations.

Again, with the order of operations. It's not a thing. I've given you two examples that don't follow any.

The constructivist learners...

That's kinda random, but sure?

And many proofs of other rules...

They all derive from each other. Even those fundamental properties are. For example, commutation is used to prove identity.

But the order you apply operators does matter

2+2-2 = 4-2 = 2+0 = 0

2 operators, no order followed.

If we take your example

2+3×4 then it's not an order of operation that plays the role here. You have no property that would allow for (2+3)×4 to be equal 2+3×4

Look, 2+3×4 = 1+3×(2+2)+1 = 1+(6+6)+1 = 7+7 = 14

Is that not correct?

Notably you picked...

It literally has subtraction and distribution. I thought you taught math, no?

2-2 is 2 being, hear me out, subtracted from 2

Same with 2×(2-2), I can distribute the value so it becomes 4-4

No addition? Who cares, subtraction literally works the same, but in opposite direction. Same properties apply. Would you feel better if I wrote (2-2) as (1+1-2)? I think not.

Also, can you explain how is that cherry-picking? You only need one equation that is solvable out of order to prove order of operation not existing. One is conclusive enough. If I give you two or more, it doesn't add anything meaningful.

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[–] SmartmanApps@programming.dev 1 point 1 year ago* (last edited 1 year ago)

At least that’s not how I’ve been taught in school

If you had a bad teacher that doesn't mean everyone else had a bad teacher.

You’re not teaching kids how to prove the quadratic formula, do you?

We teach them how to do proofs, including several specific ones.

No, you teach them how to use it instead.

We teach them how to use everything, and how to do proofs as well. Your whole argument is just one big strawman.

Again, with the order of operations

Happens to be the topic of the post.

It’s not a thing

Yes it is! 😂

I’ve given you two examples that don’t follow any

So you could not do the brackets first and still get the right answer? Nope!

2×2×(2-2)/2=0

2×2×2-2/2=7

That’s kinda random, but sure?

Not random at all, given you were talking about students understanding how Maths works.

2+3×4 then it’s not an order of operation that plays the role here

Yes it is! 😂 If I have 1 2-litre bottle of milk, and 4 3-litre bottles of milk, there's only 1 correct answer for how many litres of milk of have, and it ain't 20! 😂 Even elementary school kids know how to work it out just by counting up.

They all derive from each other

No they don't. The proof of order of operations has got nothing to do with any of the properties you mentioned.

For example, commutation is used to prove identity

And neither is used to prove the order of operations.

2 operators, no order followed

Again with a cherry-picked example that only includes operators of the same precedence.

You have no property that would allow for (2+3)×4 to be equal 2+3×4

And yet we have a proof of why 14 is the only correct answer to 2+3x4, why you have to do the multiplication first.

Is that not correct?

Of course it is. So what?

It literally has subtraction and distribution

No it didn't. It had Brackets (with subtraction inside) and Multiplication and Division.

I thought you taught math, no?

Yep, and I just pointed out that what you just said is wrong. 2-2(1+2) has Subtraction and Distribution.

2-2 is 2 being, hear me out, subtracted from 2

Which was done first because you had it inside Brackets, therefore not done in the Subtraction step in order of operations, but the Brackets step.

Also, can you explain how is that cherry-picking?

You already know - you know which operations to pick to make it look like there's no such thing as order of operations. If I tell you to look up at the sky at midnight and say "look - there's no such thing as the sun", that doesn't mean there's no such thing as the sun.

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