idk what country the poster or you are from but, in Ireland anyway, we'd almost never say subtraction and say take away or minus instead. so I'd say it depends on where you're from and what you're taught
I might be wrong but it looks like they have to round 12 up to 15 for some reason and then move up by 10s until they get to 30 then add 2 because that gets you to 32?
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Edited 6 years ago
deleted
· 6 years ago
Long post below, but that's exactly right. It's less about memorizing simple math, and more about learning the relationships between numbers, and (almost philosophically) why math works.
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deleted
· 6 years ago
So, a lot of people have problems with the "New Way" )AKA CommonCore), because it's hard to understand, it's new and foreign, and most parents suddenly have no way to help their kids with math homework.
What's boring and hard to explain to people emotionally put off by the new way being hard, is that this is actually a more effective long-term method for teaching principles of mathematics to children.
One of the (really advanced) aims of CommonCore is not necessarily to teach kids how to get to the answers, but to expose children to as many possible neural pathways for getting to the answer as possible. In this example, students will be writing out the shortcuts that the brain builds naturally.
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deleted
· 6 years ago
We need to know the difference between 32 and 12, and we work in base 10. Let's get from 12 to the next ten in as few easy steps as we can. Half of ten is 5, so let's move to the next 5. After 12, that's 15 (difference 3). The next ten is 20 (difference 5). Add another 10 to get to 30 (difference 10) and then 2 more gets us to 32 (difference 2).
Add the difference from each of those steps and we will know how far 12 is from 32.
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It's more complicated. Heck, it's MASSIVELY more complicated. However, going through these processes, understanding the relationship between addition and subtraction, getting a base for how to use algebra (at age 7!), and seeing on paper the steps that get you there, build a firmer base for long-term use of math.
It's way more advanced than 32-12, 2-2=0 in the ones place, 3-1=2 in the tens place. 20.
The "Old Way" only tests single digit addition, and no higher level thinking skills.
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deleted
· 6 years ago
The "New Way" is all about meta-learning, or learning about how your brain learns, which is philosophically too deep to explain to the average parent who is freaking out because they can't understand their kids' math homework.
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To be fair, 99% of the teachers issuing these assignments hardly understand them themselves. They've never learned that way, and now they're teaching it.
The rollout of CommonCore was forced, faulty, sudden, and unplanned-for.
That's the real disaster.
Sorry for the long post, 32 potatoes minus 12 potatoes equals 20 potatoes.
@unklethan "In this example, students will be writing out the shortcuts that the brain builds naturally." If the brain builds those shortcuts naturally then it doesn't seem necessary to forcefully teach them.
However, if a student is struggling then it seems worthwhile to evaluate whether such mental shortcuts are actually being built, and if not THEN teach them. This so called "new way" seems to have more of a place in a remedial setting.
I agree that the underlying mathematics and the relationships between addition/subtraction/multiplication/division is something that students should come to understand if they are to be truly successful. However, bringing the entire class down to a remedial level is just as unfair to those who excel as it would be to those who struggle if the whole class were raised to an advanced level.
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deleted
· 6 years ago
One thing to remember is that this isolated example of "The New Way" is actually just one of the new methods being taught. Kids are learning as many ways to subtract 12 from 32 as can be reasonably taught in one school year.
If one method doesn't stick with 1/2 The students, then another method might.
It's also important to remember that these are just concepts. Students are also expected to do the rote memorization that the generation before them did.
Couple memorization of the material with an understanding of how math works, and we might just raise up a generation that doesn't hate math.
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deleted
· 6 years ago
I highly doubt the last part will ever come to fruition
I really appreciate this explanation, I feel like people who seem to actually hate the "new way" are just put off by not understanding it, or it not being traditional, but it'll make this next generation better for it
It seems like it takes a lot more time and I am not about that. I'll stick to the basics, the younglings can deal with this shit I'm out of school.
7Reply
deleted
· 6 years ago
They introduced this nonsense in Alberta a few years ago, it was recently revealed that our math scores have fallen every year since. 20 years they've been teaching this and just last month it was announced it will be scrapped.
Just an unlucky generation I guess.
Here's a different example of this method for those who wonder why it's taught this way: 600-50=? This is so simple for most of us that we don't write it down. In our heads we start at 50. We add 50 to get to 100. Then we count by 100s to get to 600. So our counting would sound something like "50, 100, 200, 300, 400, 500, 600." One 50, five 100s. Our answer is 550. For this problem, all the writing says is "12, 13, 14, 15, 20, 30, 31, 32." Three 1s, one 5, one 10, two more 1s. 3+5+10+2=20. It's a method for doing the math in yoir head, most of us do it this way everyday. We've just never seen it written out so it looks strange.
deleted
· 6 years ago
I never did it like that, I don't add to substract
This is a unit counting method, it's a different method from straight subtraction. It's easier to figure out "9362 - 8735" in your head when you're not crossing out amd carrying.
yes, this looks rediculous with easy numbers like 32 and 12. But when you learn this concept and get good at it, you can do problems like 645-297 quickly in your head.
Everyone mad or downvoting comments are just butthurt they can't understand this, I don't understand it either, honestly, but that just means the next generation's probably gonna be smarter than us, so good
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deleted
· 6 years ago
Have you ever heard, work smarter not harder? Why go out of your way to do something like this when you could do it normally
This is working smarter, it'll help them in the future to do the problems of the in there head such as a bunch of people have said on these comments, school isn't supposed to just be easy so the kids can get good grades, it's supposed to prepare them for the future, the future is hard, and that whole "work smarter, not harder" thing is bullshit, work smarter and harder and maybe we'll get more shit done
That makes no sense. You're saying "if there's an easier way to do something that would produce the same result, and would require less energy, don't do it"? That's bullshit
But it's not the same result, for one, not in this situation at least, and two, to have that principle means that you're always gonna be looking for an easy way out, yes, sometimes there are easier ways with the same result, but we should be already ready to work hard as fuck if there's not, in this situation the result of common core is that in the future these kids will be more logical thinkers, so let's have them work hard so they can have better principles, working harder and not just working smarter (yes I still think we should work smarter) creates a better foundation, which is what children need
The principles part had more to do with the "work harder, not smarter" part, but it does help them think more critically, make more connections, make better decisions, which ultimately makes them a better person, rather than it just being about getting good grades
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deleted
· 6 years ago
Nothing you says has no correlation with anything at all, solving math problems doesn't help you to face hard things in life. And the work harder not smarter is complete bullshit, in real life, when you work, you HAVE to work smarter, to gain time, energy and money, by working smarter you work harder
1
deleted
· 6 years ago
Heaven forbid someone work harder now in order to work smarter over their lifetime. It's almost like those crazies are investing in themselves. Darn Communists.
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deleted
· 6 years ago
You've completely misinterpreted the saying and made yourself sound stupid
2
deleted
· 6 years ago
"That makes no sense. You're saying "if there's an easier way to do something that would produce the same result, and would require less energy, don't do it"? That's bullshit"
I learn from the best ;)
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deleted
· 6 years ago
Just repeating me also makes no sense. Back up your claim with evidence from the text, Mr. Condescending Winky Face
It works better with larger numbers. It takes less time. It just looks stupid here, with simple numbers. Have you actually learned the method? Just because it's unfamiliar doesn't mean it's wrong.
What's boring and hard to explain to people emotionally put off by the new way being hard, is that this is actually a more effective long-term method for teaching principles of mathematics to children.
One of the (really advanced) aims of CommonCore is not necessarily to teach kids how to get to the answers, but to expose children to as many possible neural pathways for getting to the answer as possible. In this example, students will be writing out the shortcuts that the brain builds naturally.
...
Add the difference from each of those steps and we will know how far 12 is from 32.
...
It's more complicated. Heck, it's MASSIVELY more complicated. However, going through these processes, understanding the relationship between addition and subtraction, getting a base for how to use algebra (at age 7!), and seeing on paper the steps that get you there, build a firmer base for long-term use of math.
It's way more advanced than 32-12, 2-2=0 in the ones place, 3-1=2 in the tens place. 20.
The "Old Way" only tests single digit addition, and no higher level thinking skills.
...
---
To be fair, 99% of the teachers issuing these assignments hardly understand them themselves. They've never learned that way, and now they're teaching it.
The rollout of CommonCore was forced, faulty, sudden, and unplanned-for.
That's the real disaster.
Sorry for the long post, 32 potatoes minus 12 potatoes equals 20 potatoes.
However, if a student is struggling then it seems worthwhile to evaluate whether such mental shortcuts are actually being built, and if not THEN teach them. This so called "new way" seems to have more of a place in a remedial setting.
I agree that the underlying mathematics and the relationships between addition/subtraction/multiplication/division is something that students should come to understand if they are to be truly successful. However, bringing the entire class down to a remedial level is just as unfair to those who excel as it would be to those who struggle if the whole class were raised to an advanced level.
If one method doesn't stick with 1/2 The students, then another method might.
It's also important to remember that these are just concepts. Students are also expected to do the rote memorization that the generation before them did.
Couple memorization of the material with an understanding of how math works, and we might just raise up a generation that doesn't hate math.
Maybe the new way is they are trying to make kids like Math?
Just an unlucky generation I guess.
I learn from the best ;)