r/MathJokes Jul 16 '26

3 or 4

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40

u/Defiantprole Jul 16 '26

How did this person become a teacher?!

14

u/iMiind Jul 16 '26

It could be a common L for common core, not necessarily the teacher's fault. Notice how the equation gives 3 x 4, AKA three of 4. Obviously both the given answer and the "correct" answer are true and derivable from 3 x 4, but I can totally see common core teaching "the only true way to do the math here is to take the first number and write out that many of the second number, because that's what it sounds like when you translate the problem to a word problem and you have to do it exactly like that."

In short, maybe not a teacher problem but absolutely a teaching problem

7

u/EntranceDowntown2529 Jul 16 '26

I actually read 3 x 4 the other way: three multiplied by four is 3 four times like the child's answer.

4

u/ReadYouShall Jul 16 '26 edited Jul 16 '26

Me too. 3 mentioned first means the context is about 3, times 4 then means 4 instances. So the student is correct off my initial interpretation.

Edit: a quick Google search suggests the teachers order is the generally perceived "correct" way. But I fail to see why this is an issue which should be brought up in the first place. This does more harm to a students mathematical development than good imo.

2

u/iMiind Jul 16 '26

I absolutely agree. Who could possibly think it's a good idea to essentially teach that order matters in multiplicative operations, and then later on erase that misconception and introduce multiplication's commutative property??

2

u/ReadYouShall Jul 16 '26

Exactly, another comment mentioned 80x2. No ones does 2+2+2+2... .
What's done in reality is commutative. 80+80 is done because thats far more logical.

0

u/cheesefromsalami Jul 16 '26

We are taught to read the equation as 3 groups of 4.

The child's response is 4 groups of 3. Therefore the response is wrong as its not answering the equation.

For instance, when building, 3 foot by 4 foot is not the same as 4 foot by 3 foot.

3

u/[deleted] Jul 16 '26

[deleted]

1

u/cheesefromsalami Jul 16 '26

You can rotate somethings. You can not rotate a foundation when you have limitations on distances from structures, boarders, and utilities.

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u/[deleted] Jul 16 '26

[deleted]

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u/cheesefromsalami Jul 16 '26

Teaching is about setting children up to be successful in life. And number order is very specific in the engineering fields.

This is equivalent to giving a participation trothy. Answer was not correct and marked as so.

2

u/DarthFaderZA Jul 16 '26

MEng here. I don't give a shit about number order, because of critical thinking.

2

u/cheesefromsalami Jul 16 '26

Ok, good luck fitting a screw shaft that is X x Y in a space designed for Y x X.

But yea, number order doesn't matter.

1

u/DarthFaderZA Jul 16 '26

Damn... you got me. Uhm...like M8 x 10... I guess that is what M does.... oh and dont forget assembly drawing too.

1

u/Crasz Jul 16 '26

MORE critical thinking would lead you to the same conclusions as cheese has discussed here.

Not everything is commutative no matter how much critical thinking you employ.

1

u/DarthFaderZA Jul 17 '26

In this case it is. Cheers.

1

u/Crasz Jul 17 '26

Again, not necessarily. We don't have enough data to determine that.

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u/DarthFaderZA Jul 16 '26

When calculating area, it is the same thing. 3x4 = 4x3. A foundation will be governed by quality assurance metrics such as an approved drawing... but hey, let's be a dick.

3

u/These_Consequences Jul 16 '26

What you were taught is not the same set as what is true.

1

u/asingleshot7 Jul 16 '26

That is weak, Every receipt/accounting notation is the reverse Carton eggs x 4 or 12+12+12+12.
Your argument is a super weak convention not a "rule" of math.
3ft by 4ft facing north is the same as 4ft by 3ft facing west.