Common core is not a curriculum. It is not a textbook. It is not a method of subtraction. There are badly-written textbooks both in and outside of Common Core.<p>Edit: Here we go, Common Core math standards. Grade 2 starts on page 17. <a href="http://www.corestandards.org/wp-content/uploads/Math_Standards.pdf" rel="nofollow">http://www.corestandards.org/wp-content/uploads/Math_Standar...</a> Have a look, it's only 4 pages long.<p>To be specific, this is a third-grade textbook. Students learn subtraction in previous grades, so this is just a quick review before moving on to third-grade topics like multiplication. Notice the problems at the bottom don't require students to use this particular method. If your third-grader can't subtract, they were already behind before you switched to Common Core.<p>Also, is the method given really that hard to understand? It's probably not my favorite way to subtract, but it's kinda cool.
This seems like generated outrage.<p>The OP should take a minute to think about how the method of subtraction works, and then explain it to his kid.<p>I associate this panic reaction (OP: "this new method makes no freaking sense") with people who are math-phobic. The solution is to just settle down and think about it. (Common core, third grade objectives, number 1: "Make sense of problems and persevere in solving them.")<p>And, one thing I've learned about elementary educators is that they don't want to fight with parents. (Unsurprising!) So if you say (like OP did), "This common core math sucks," they are going to say, "yes, we don't like it either." If you said it was an interesting way to do subtraction, they'd agree with that too.
Back in the days before computerized cash registers, this was typically how cashiers made change. Hand one $5 for a $1.34 purchase, and the cashier counts it back out as<p>(penny) $1.35
(nickel) $1.50
(quarters) $1.75, $2
(dollar bills) $3, $4, $5<p>Some still do it that way.<p>In <i>Teacher in America</i>, chapter "Let <i>x</i> Equal ...", Jacques Barzun mentioned as an example of widespread innumeracy the half-trained cashiers who did not know this technique. That was written in the early 1940s.
As a homeschooler I think Common Core is a good thing in that it tells you what you need to cover, and it means that I can choose from a lot of different curricula which include it.<p>If you work through Kahn Academy math, you will certainly run through some of these areas where kids are pushed to do some kind of math problem in a highly stylized way that (i) they struggle with and (ii) don't see the relevance of. Elementary school teachers have told me the same thing, but it is not the end of the world.<p>There is "no one true way" to do arithmetic. When I was in the fourth grade I had the worst time with 3-by-3 digit multiplication. That didn't stop me from getting a B.S. in Physics and Math, with an A average in my majors, and also getting a PhD in theoretical physics. Recently I read that a lot of other people who were "good at math" struggled with the curriculum when I was a kid so nothing is going to be perfect.
I'll echo the comment that Common Core is not a textbook nor a particular way to add/subtract. It's a standard to establish baseline knowledge US kids must master.
That blog post is raging about a new way to do subtract which seems to be out of reach for his comprehension, can't teach an old dog kindda thing, so he blames it on Common Core.
He also mentioned that there are 4 new ways to do subtraction. This should be good news. Kids/people learns to do things differently. 4 different ways means kids have more arsenals to tackle their problems. I wish I had that learning opportunity!
Specifically about that subtraction, did you noticed that it'd make it easier to do the math in your head? maybe there is a reason for the madness after all.
Common Core is just fine as a set of standards and has a good shot at being adopted around the world, so we need to get over it. Common Core is going to lead to a lot more innovative solutions, because the market of students on it will be large. It's very nice from a computer science standpoint as well. Check out the game we built at Zeal. While it's a nice simple game on the surface, behind the scenes we are maintaining a complete map of everything every child has mastered in Common Core Math and Literacy K-8, which lets us figure out an ordering of skills to learn and what to do if a child is struggling on a given skill. This is the kind of thing that has been solved in every other industry, but Common Core enables in education.
> They cannot help their children. The math makes no sense and seems to offer no practical purpose other than it is new.<p>First of all parents were not able to help their children with old methods either. Give someone a pen and paper and ask them how to add 17% to 58. You don't want an answer - just a working method. A lot of people can't do this on paper, but that's okay because we have computers to do that stuff. Lots of people can't add 17% to 58 using a computer. I find that a bit scary.<p>Going on to the example: I'm pretty stupid; I've often said that I am hopeless at math. I found that single example really easy to understand. I've not had any exposure to similar examples. I don't believe the author is actually baffled by the example. Perhaps a book might help?<p><a href="http://www.robeastaway.com/books/maths-for-mums-and-dads" rel="nofollow">http://www.robeastaway.com/books/maths-for-mums-and-dads</a><p>> What on earth are number bonds? What are partitioning and chunking? And why does my child look blank - or have a tantrum - when I demonstrate long multiplication? This book is for mums, dads and grandparents who want to help their primary school children or grandchildren with maths. To do so, many parents find they need to overcome their own rustiness and also to learn the strange new methods and terminology. Throughout the book are games, puzzles and examples of amusing ways in which kids ingeniously 'get it wrong'.
While I agree that one example is not enough to grasp the concept for most people, I think that the "counting up" method is actually better because it shows kids what is going on in subtraction.<p>The borrowing method that I learned growing up doesn't make much sense. You just follow the rules with no real reason.<p>I'm in my third year of college and only just learned why the borrowing method works - and I only learned it because I had to start subtracting numbers in different bases for my MIPS assembly class.
Perhaps more disturbing than the author's inability to understand a simple procedure in a third-grade math text is his attempt to cast Common Core as part of an overarching conspiracy of corporations and (of course) government to turn our little ones into docile robots. This is what a nut case looks like.
The first two paragraphs illustrate a huge problem with US math education, which pre-dates common core, but is reinforced by it.<p>That problem is the false belief that numeracy is improved by learning different ways of looking at number operations. (i.e. four ways to subtract).<p>Our child's second-grade teacher (a very good teacher) has a poster illustrating 7 ways to subtract. Seven ways, no exaggeration. This poster is older than common core.<p>Students learn math just like they learn to kick a ball. By practicing. Learn one way to subtract, and practice it really really well. Or learn two ways, and practice each way really, really well. Learn more ways if you want, but practice each way really really well. Most math curriculums assume that learning multiple ways is equivalent to (or better than) practicing one way. They don't require the repetitive practice.<p>As comments have pointed out, the common core standards don't explicitly require this multi-way approach. But the CC standards compound the problem by requiring students to <i>explain</i> concepts in order to demonstrate mastery. Completing lots of subtraction problems with a low rate of error doesn't count. You must <i>explain</i>, in order to understand. And if you <i>really</i> understand, shouldn't you be able to explain different approaches?<p>I would say no. Or at least, not yet. I don't want a third-grader explaining how to subtract unless they can also finish 50 subtraction problems in a row without pausing to struggle. And if they get the problems right? Good job, you get an A. Wonderful, let's skip grading the explanation because that is subjective as hell.<p>TL/DR: The article rightly points out a crap way to teach math. Common core is not totally to blame, but it makes a bad problem worse.
I wouldn't fault Common Core. I'd fault the textbook. That little page on counting-up subtraction didn't make sense to me either, so I went to Wikipedia, read this shorter snippet[1], and understood it immediately. That textbook's just crappy.<p>[1] <a href="https://en.wikipedia.org/wiki/Subtraction#Counting_up" rel="nofollow">https://en.wikipedia.org/wiki/Subtraction#Counting_up</a>