# What's up with this new math

Da heck?

#### KeithTalent

##### Elite Member | Administrator | No Lifer
Boy, I'm really tired today, so maybe that's it, but I have no fucking clue what is going on in "The 'New' Way".

KT

#### OCGuy

##### Lifer
I doubt that is new and who is using that as a new way?

#### SlowSpyder

##### Lifer
I doubt that is new and who is using that as a new way?

My second grader brings home some math homework that is completely unfamiliar to me from time to time. D:

That's dumb.

Wut?

#### techs

##### Lifer
I though the new math was do it on your computer?

#### SaurusX

##### Senior member
The best way to learn is not through these stupid algorithms, but through the old time tested methods. You can come up with something like this on your own and use it in your head after you've got the fundamentals down.

#### EvilYoda

##### Lifer
Is this that "math core" stuff I see people talking about on my FB page? WTF?

#### dave_the_nerd

##### Lifer
I don't understand where those numbers are coming from.

#### dave_the_nerd

##### Lifer
Is this that "math core" stuff I see people talking about on my FB page? WTF?
Probably just an internet hoax.

I worked in elementary schools for years and never saw anything like this.

#### lozina

##### Lifer
I see what they're doing... but don't understand why.

It's like you are driving from point A to point B and think you are simplifying it by only a bunch of long windy right turns when all you needed to do was one left.

#### Mark R

##### Diamond Member
Yeah. This is the new fad in education. Round here, they call it "clustering" - basically, you convert 1 problem, into a "cluster" of simpler problems with nice round answers.

So, in this case, to subtract 12 from 32, you would break the problem into a bunch of simpler problems.

Take 12, now choose a number than when added, gives a nice round number.
In this case, 15 is a close "round" number, so you add 3.
20 is an nice round number closer to your target - add 5
30 is another nice round number, closer to your target - easy. Add 10

Now add everything else up 3 + 5 + 10 + 2.

--

You should see how convoluted this method gets when teaching multiplication.

If you're good at mental arithmetic, you often develop your own "shortcuts" or ways to break a problem down into simpler methods.

E.g. to multiply by 9, you could multiply by 10, then subtract the original number.

This is what "clustering" is all about. Teaching children to make up their own methods to work around problems.

--

In my view, this should be taught at an advanced stage. It can be confusing, it's certainly unfamiliar to most adults, and it has the problem that it might not work in certain circumstances.

The advantage of traditional methods, is that they always work, are simple to understand, although they may be more difficult to perform.

#### Imported

##### Lifer
Uhh.. WTF. My brain hurts looking at the "new" way.

#### purbeast0

##### No Lifer
Yeah. This is the new fad in education. Round here, they call it "clustering" - basically, you convert 1 problem, into a "cluster" of simpler problems with nice round answers.

So, in this case, to subtract 12 from 32, you would break the problem into a bunch of simpler problems.

Take 12, now choose a number than when added, gives a nice round number.
In this case, 15 is a close "round" number, so you add 3.
20 is an nice round number closer to your target - add 5
30 is another nice round number, closer to your target - easy. Add 10

Now add everything else up 3 + 5 + 10 + 2.

--

You should see how convoluted this method gets when teaching multiplication.

If you're good at mental arithmetic, you often develop your own "shortcuts" or ways to break a problem down into simpler methods.

E.g. to multiply by 9, you could multiply by 10, then subtract the original number.

This is what "clustering" is all about. Teaching children to make up their own methods to work around problems.

--

In my view, this should be taught at an advanced stage. It can be confusing, it's certainly unfamiliar to most adults, and it has the problem that it might not work in certain circumstances.

The advantage of traditional methods, is that they always work, are simple to understand, although they may be more difficult to perform.

what you explained is much more complicated than...

3-1 = 2
2-2 = 0

then putting them next to each other for 20. (as the old way shows)

makes absolutely no sense to do it the new way.

#### rh71

##### No Lifer
Surprised I hadn't seen it discussed here before. It's called Common Core and many states have adopted it, but many parents and teachers are also fighting it. Anyway, the way they arrived to the numbers... think of what adds to the previous number to get to the next # in multiples of 5 or 10. Target is 32.

12+? = 15 ... you started at 12 so you would need 3 to get to 15 (multiple of 5).
15+? = 20 ... take that 15 you got to and how many gets you the next multiple of 5 or 10? 5
20+? = 30 ... take that 20 and how many gets you to the next multiple of 5 or 10? 10
30+? = 32 (target) ... take that 30 and how many gets you to your target? 2

Now add all those in bold above.

If written out like this, it does seem overly complicated, but it is designed to make you think broadly. How many times have you had some obscure numbers like 32 and 12 in your head? Instead of adding one on top of the other, you can say 32 is close to 30 and 12 is close to 10. It's easier adding multiples of 5 or 10 like that... so you have 40 and you had left off 2 from each number before... 40+4 = 44. Same shit, different way designed to make you think deeper. Subtracting large obscure numbers in your head would make it an even better example.

I'm sort of on the fence about common core... many parents say their kids are 1) overly frustrated and bringing down an otherwise bright child or 2) took 100 steps to arrive at something that normally takes 2. But they are missing the point of the exercise. On the other hand, this is also about revenue for those behind putting this in place.

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#### child of wonder

##### Diamond Member
Don't fix what isn't broken.

#### benzylic

##### Golden Member
The "new way" looks like the method the cashier at McDonalds uses when I give him \$20 to pay for my \$6.53 Big Mac.

\$0.47 makes \$7
\$3 makes \$10
and \$10 makes \$20

#### highland145

##### Lifer
The "new way" looks like the method the cashier at McDonalds uses when I give him \$20 to pay for my \$6.53 Big Mac.

\$0.47 makes \$7
\$3 makes \$10
and \$10 makes \$20
Heh, doubtful because the register does it for them. That is the way I count change to my customers though.

#### lozina

##### Lifer
Just in: Trees nationwide begin protests against the "new math".

#### dave_the_nerd

##### Lifer
Surprised I hadn't seen it discussed here before. It's called Common Core and many states have adopted it, but many parents and teachers are also fighting it. Anyway, the way they arrived to the numbers... think of what adds to the previous number to get to the next # in multiples of 5 or 10. Target is 32.

12+? = 15 ... you started at 12 so you would need 3 to get to 15 (multiple of 5).
15+? = 20 ... take that 15 you got to and how many gets you the next multiple of 5 or 10? 5
20+? = 30 ... take that 20 and how many gets you to the next multiple of 5 or 10? 10
30+? = 32 (target) ... take that 30 and how many gets you to your target? 2

Now add all those in bold above.

If written out like this, it does seem overly complicated, but it is designed to make you think broadly. How many times have you had some obscure numbers like 32 and 12 in your head? Instead of adding one on top of the other, you can say 32 is close to 30 and 12 is close to 10. It's easier adding multiples of 5 or 10 like that... so you have 40 and you had left off 2 from each number before... 40+4 = 44. Same shit, different way designed to make you think deeper. Subtracting large obscure numbers in your head would make it an even better example.

I'm sort of on the fence about common core... many parents say their kids are 1) overly frustrated and bringing down an otherwise bright child or 2) took 100 steps to arrive at something that normally takes 2. But they are missing the point of the exercise. On the other hand, this is also about revenue for those behind putting this in place.

OIC.

Yeah, we just use those stupid counting blocks.

Maybe they'll start the common core stuff next year. That'll be fun.

#### OCGuy

##### Lifer
The "new way" looks like the method the cashier at McDonalds uses when I give him \$20 to pay for my \$6.53 Big Mac.

\$0.47 makes \$7
\$3 makes \$10
and \$10 makes \$20

You must be posting from 1955, because cashiers don't do that kind of math.

However, give them \$22.03 for that meal, and watch the sheer panic/confusion.

##### Lifer
On the other hand, this is also about revenue for those behind putting this in place.

I'm betting this is the real answer.

#### lozina

##### Lifer
However, give them \$22.03 for that meal, and watch the sheer panic/confusion.

That's about as mean as tying a piece of smoked ham on a dog's nose