Common core

You find the typical method simple because you've been doing it for 10+ years.

subtraction is just done via 2's compliment addition in most (all?) CPU's ALU. Not exactly analogous to this counting-up subtraction bullshit.

Common core methods are trivial to people who are actually good at math, but just retardedly confusing to people who aren't. The end result is extremely ineffective.

Please explain how division is a form of "fancy adding".

>but my takeaway 1's

This is a good method for mental subtraction.

Also what does this have to do with common core? Common core is a set of broad guidelines, not specific techniques.

Division is just repeated subtraction, which is just repeated addition.

But in the context of this method it is objectivly less simple to do a multi step operation than a single step one like with traditional subtraction.

common core does not specify a specific method or alogrithm

blame the book writers, not the standards

I will, it's a great method for arithmetic. The only problem is it looks harder to your average brainlet, but observe:
>325-38 = 325-(40-2)=325-40+2=325-20-20+2=287
So instead of a digit-by-digit computation we've reduced the problem to a couple of trivial operations. On the surface it looks like you've made more work for yourself but because the brain is not a computer this way ends up being much more efficient.

There is nothing hard about common core, its a lot better than the traditional methods, its just that people are morons.

You used subtraction thus not using the method properly. But ill give you a partial score of 1/4 for making it look like common core.

Hmmmm, i probably should have paid more attention to the OP. Its a neat method, but mine's better.

>btw this is me retracting my claim to defend it.

Traditional subtraction is not single step. It takes as many steps as the digits of the larger number plus carries. This method takes as many steps as the digit of the larger number plus one.

This is the natural way to understand subtraction (find x such that a + x = b). But if the children have understood the radix 10 representation of the number, they should have no problem understanding the working of the old method.

"Simple" and "easy" are not the same thing. One can criticize this algorithm for involving too many steps, lots of busy work, therefore it's not *easy*. But the concept itself is immediately clear for anyone who can add, therefore it's *simple*.

It would be better if they subtracted 25 first and then 13, which I think is simpler and easier

Like you haven't been using these methods. They just weren't teached becouse students back then were not sub 100 IQ subhumans.

>subhuman
>sub 100 IQ
>not sub 140 IQ
Disgusting. Don't talk to me or my wife's image board ever again.

The simpler solution is 100% worthless. It's not applicable to larger problems, and it does not teach problem solving and decomposition, crucial when writing programs. Common core has a lot of issues, but it really has the right idea.

325 - 38 = 325 -25 -13 = 300 -13 =287

325-8= 317
317 - 30 = 287
Wow it's even easier.

>Common core methods are trivial to people who are actually good at math, but just retardedly confusing to people who aren't. The end result is extremely ineffective.

That's why you train people to adopt the common core method of math. This is a whole new of style of thinking, you can't expect to learn it overnight. That's like expecting to be a physicist in just a couple semesters of physics. You have to practice this.

It's too early to be talking about the end result.

practice what, adding and subtracting integers?

It's just one of many methods that they cover. The idea is that they try to give students and intuition for how numbers can be worked with rather than one specific process.

youtube.com/watch?v=tBkQAxt1JXA

This is taught to elementary schoolers. Children who are naturally good at math will come up with some form of this method in their head anyway. For them, learning this doesn't do any harm, they might just be bored in class a few days. Many kids despise math (and consequently science) because they just never "got" it. This is a way to sorta bring these kids up and make them not regard math and science with fear and anxiety.

> because they just never "got" it.
in otherwords CC is SpEd.

>Calling other people speds.
>Using a space between your text and your meme arrows.
kys yourself

>implying syntax nazis aren't sped autists
seek help

wow I fail to believe someone can be educated enough to read those words but not know subtraction

>Failing to use proper capitalization and punctuation.
Your argument is literally
>I may appear retarded but only a retard would go out of their way to tell me that.

If you can't see how/why this works

>being so autistic that you get this triggered by unconventional syntax and grammar on a taiwanese cartoon debate forum
i'm glad i'm not you.

inb4 it's called anime

Yes, please double down on your retardation. It really helps solidify your argument that you know how the education system should be operated.

take your meds

Instead of doing 325-38, you do 38+x=325, and you do it in small enough pieces that its all easy to do. Specifically, you keep adding numbers until you get to an even 10, or 100, and then add what's needed to get you the rest of the way.

38+2=40, so now we're at a 10.
40+60=100, so now we're at a 100. Time to get to where we need to
100+200=300 gets us the right 100
300+25=325 gets us the rest of the way.

So, in total we have 38+2+60+200+25=325. Since addition is typically easier than subtraction, we get 38+287=325.

If you're clever, you could of course do this more efficiently:

38+7=45
45+280=325

280+7=287

Which is actually how I do it in my head.

What works for different people I suppose. What I object to is children being marked wrong on correct answers because they used the 'wrong' method. Different people learn in different ways and mentally work through problems differently, more than one approach is valid. After telling teachers they should 'differentiate' for pupils they shouldn't be now marking kids down for not all following the exact same approach.

Degree in math here; this is exactly the algorithm I use to do subtraction in my head. Why do retards like always say the new way of doing these things is OH SO HARD AND COMPLICATED? It's literally so intuitive that I started doing this method early on without even being told.

btw, this method is literally the simplest method to calculate change at a point-of-sale.

>Thing is $17.18
>Guy hands you $20

Ok, hold on to your hats because this is apparently where things get too difficult for the average Veeky Forums user.

>A nickel and two pennies gets me to $17.25
>3 quarters gets me to $18
>Another 8 quarters or two $1 bills gets me to $20

It's so fucking easy, and yet the majority of people cannot do this sort of thing without an auto-teller or calculator.

Well because I brute force match really fast. I just know the solution don't have to use the tricks

This.

>Which is actually how I do it in my head.
This is exactly the point of teaching different common core techniques.

There's two reasons I can see that happening.

1) The teacher themselves not understanding the new approach to mathematics teaching and marking the students off for frivolous reasons.
2) The teacher wanting to cover a certain number of techniques and marking off the students who only learn one technique and ignore the others.

In the first case I agree with you that kids shouldn't be marked off for frivolous reasons. In the second case it makes sense that if you expect a student to understand a certain method then you should grade accordingly.

>brute force match
wat?

>This is a good method for mental subtraction.

It's not. If you want to subtract by adding then do 10's complement.

Counting up is supposed to help you realize that a-b=x is the same as a=b+x i.e. the difference 'x' is how much more 'a' is than 'b'

Why on earth wouldn't you just break 38 into 25 and 13, then subtract 13 from 300?

This is the approach I use as well.

Funny thing is though that both methods and many others are taught in common core.

>this shit again

There are two acceptable methods.

38-25 = 13
300 - 13 = 287

325 - 30 = 295 ||| 325 - 8 = 317
295 - 8 = 287 ||| 317 - 30 = 287

Anything else is needlessly complicated.

This

Playing with numbers and finding different solutions/algorithms for the same thing.

/thread

Yes cc does have the Veeky Forums stamp of approval. But you already knew that didn't you. What's the point of this thread again?

>sci will defend this

No they will not
>adding all those numbers.

Just do 325 - 8 = 317
317 - 30 = 287