Jennie should learn math

[TheTominator]

At least Jenny knows 8675309.

[Ombligo]

M A V I C wrote:

But while we're at it, what's 10*2+15/5+6*4-10=?

It's sad that when I see those questions on FB, most people get them wrong.

Well yeah, fFB won't give them the answer, they need to go to Mathway.com to be told it is 37 - no thinking needed. that's the modern math

[graylocks]

space-time wrote:
So kid comes home and starts homework, one of the questions was something like "Jennie doesn't know multiplication tables, and how you can help her understand 8x7" or something like that. There were several answers, the correct was was to split the 7 into (2+5); Jennie knows 8*2 and 8*5 and add up the results.

My son figured out the correct answer, but he also wrote:

how is it that Jennie knows 8*2 and 8*5 if she doesn't know multiplication tables? why are there such gaps in her education? is splitting into 2+5 the ONLY correct answer?

[N-OS X-tasy!]

space-time wrote:
So kid comes home and starts homework, one of the questions was something like "Jennie doesn't know multiplication tables, and how you can help her understand 8x7" or something like that. There were several answers, the correct was was to split the 7 into (2+5); Jennie knows 8*2 and 8*5 and add up the results.

If Jennie doesn't know multiplication tables, how does she know 8*2 and 8*5?

EDIT: graylocks beat me to it!

[N-OS X-tasy!]

GGD wrote:
I would have come up with a different answer that just used addition.

7*8 is 7 left shifted 3, or doubled three times.

7+7 = 14
14+14 = 28
28 + 28 = 56

In other words, 7*(2^3).

[GGD]

N-OS X-tasy! wrote:
If Jennie doesn't know multiplication tables, how does she know 8*2 and 8*5?

EDIT: graylocks beat me to it!

My thoughts exactly, which is why I thought a solution that doesn't require any multiplication would be the best choice for an answer.

And why did they pick "Jennie" as the name, are they trying to imply that females aren't good at math?

[N-OS X-tasy!]

Onamuji wrote:
Was just having this conversation with a parent: Common Core seems to be responsible for teaching kids math via "word problems." Some of the examples seemed to be going to surprising lengths to avoid the use of any word implying a mathematical operation.

I wonder whether learning math as an extension of English vocabulary and syntax is more effective than the rote repetition of formulas that we had to do when I was a kid.

Word problems were one method used to teach math back when I learned the subject; rote repetition was another. Both methods have their merits.

When I was a kid learning math, I always felt the purpose of word problems was to illustrate to the student possible "real world" applications of mathematics. As I recall, most students vehemently hated the dreaded "word problems."

[N-OS X-tasy!]

JoeH wrote:
The "right answer" usually assumes one precedence order, I have run into half a dozen different ones over the years and have not kept up with which one is currently in favor and with which group of mathematicians. There is a reason parentheses are supposed to be used when presenting such an equation.

There is only one precedence order. It has been taught under the guise of different names over the years, but it is always the same.

[N-OS X-tasy!]

Mike Johnson wrote:
7*8 = 2*8 + 5*8 is pretty derrrr, but that’s how exactly I multiply stuff like 23*12.

Yep. 230+46= 276. Easy peasy.

[space-time]

GGD wrote:
[quote=N-OS X-tasy!]
If Jennie doesn't know multiplication tables, how does she know 8*2 and 8*5?

EDIT: graylocks beat me to it!

My thoughts exactly, which is why I thought a solution that doesn't require any multiplication would be the best choice for an answer.

And why did they pick "Jennie" as the name, are they trying to imply that females aren't good at math?
just so you don't think I made this Jennie up. We put him to erase the sentence he wrote earlier (he is already in trouble with that teacher) and write down the explanation. I should have scanned this before he erased it