6 ms·

It hit the mainstream in early 2014, when a dad in North Carolina posted a convoluted "Common Core" question from his son's second-grade math quiz on Facebook,

by parfe 12y ago

It hit the mainstream in early 2014, when a dad in North Carolina posted a convoluted "Common Core" question from his son's second-grade math quiz on Facebook, along with a letter he'd written to the teacher. "I have a Bachelor of Science Degree in Electronics Engineering which included extensive study in differential equations and other high-math applications," he wrote. "Even I cannot explain the Common Core mathematics approach, nor get the answer correct." Lunch costs $14.45. You pay with a $20. If you calculate your change without borrowing you just did common core math. The best facet of common core is the amount of adults complaining they don't understand it. Rather than an argument against, it is exactly an argument in support of teaching kids multiple ways to think about math.

boobsbr 12y ago
If you calculate your change without borrowing you just did common core math. Borrowing?
- trebor 12y ago
  The OP may mean calculating from left to right, instead of right to left. One is merely the reverse of the other. EG: $20 - $14.45 = ... $6 ($0.45 excess) $5.60 ($0.05 excess) $5.55 ($0.00 excess) Instead of: $20 - $14.45 = ... $0.05 ($14.50 total) $0.55 ($15.00 total) $5.55 ($20.00 total)
  - Practicality 12y ago
    When I learned calculating left to right it sped up so much of my daily arithmetic. I didn't learn to do that until I was 27. I feel like I wasted a lot of time doing it the hard way first.
    - AngrySkillzz 12y ago
      This is what they're trying to do with the Common Core. We should teach everyone these strategies, not just let smart people figure them out for themselves have everyone else be left behind.
      - elpachuco 12y ago
        Hyperbole Much? Left behind from where? Seriously, a couple of parlor tricks are not gonna leave anybody behind. Use a computer and devote your higher cognitive skills for more productive endeavors. Once you know the basics of how to do something you do not need to continue to get better at it if your computer can do it better for you. Learn something else with the saved time. Edit: Quick example: Is like marveling that you can do arithmetic in your head with 100 digit long numbers. Impressive? Yes. Useful? Nope. Is actually less than useful because all that time wasted you could have used it to learn something else.
        Retra 12y ago
        You're missing the point. Many maths students learn to dislike math because they cannot remember the rules, or they find them frustrating to use. They are often trying to appease the teacher by mimicking the process. Meanwhile, the better students don't bother memorizing the rules, they just focus on solving the problem. Once they see how the problem is solved, those rules either come naturally, or are supplanted by some other process that also works. This is not about parlor tricks, but about creative thinking. How do you determine whether your 'trick' works or not? How do you know if the problem is solved? Most students believe a problem is solved when they get the 'right answer' -- which often includes "doing what they were told." This is NOT how you identify a solution to a problem. The students who are left behind are the ones who never figure this out.
      - debacle 12y ago
        But they don't explain WHY! If they gave the kids even a basic bit of number theory, it would make so much more sense. If they want to teach the methods they are teaching, substitution and algebra need to be part of math from year 1 and commutativity and associativity need to be explained as more than just vocabulary words.
        sukilot 12y ago
        We tried that in the 70s. It was called New Math. It failed because parents and teachers didn't already know basic number theory. Some students (like me) were in special programs with well trained teachers, and became highly successful STEM professionals.
    - debacle 12y ago
      It's important to be able to do both.
- Kallikrates 12y ago
  "you can't subtract 5 from 0, so borrow 10 from 4, now its 5 from 10" and so on
- parfe 12y ago
  Some random gis image. http://i.imgur.com/RvAUuPK.jpg http://i.imgur.com/RvAUuPK.jpg Compare that to how you could solve the problem in your head. .01 + .70 + 6.00 For my example I bet you'd think 5¢ + 50¢ + $5.00 to compute your change.
  - parennoob 12y ago
    Firstly, I think you probably mean +0.01 +0.70 +6.00 Also, when you say the +0.01 and +0.70 there, aren't you implicitly borrowing anyway? It's just "easier" borrowing -- you say that 0.09 + 0.01 = 0.10, as opposed to explicitly borrowing the 1 to the second decimal and subtracting the 9. Similarly, you say that 0.30 + 0.70 = 1.00 instead of borrowing the 1 to the first decimal. I can see why this makes mental maths easier, but I don't see that it is any deep conceptual improvement over the borrowing. Is one of the goals of Common Core to improve mental arithmetic? If so, then this makes sense. Otherwise, unless you properly explain why the two are equivalent, and why the other method is faster, it's more like a neat sleight-of-hand trick that might leave kids slightly more confused about why it is "better" than the borrowing method. [Reference: Non-American, non-parent who knows very little about the American education system, but has some friends teaching in it.]
    - deleted 12y ago
      [deleted]
    - parfe 12y ago
      Fixed, thanks. All math solutions will be equivalent. And it isn't a parlour trick. It's teaching kids to think about breaking down problems into smaller units and composing a solution. The rote algorithms work, but training kids to execute an algorithm won't help them understand. The long form subtraction algorithm isn't a skill that carries over to multiplication. Breaking a problem into smaller components, composing a solution, and checking with your original estimate does carry over. And not just multiplication but programming as well.
- AngrySkillzz 12y ago
  Add 5 cents to get 14.50, add 50 cents to get 15, add 5 dollars to get 20. .05 + .50 + 5 = $5.55. Much easier than "1, carry the 6"
- deleted 12y ago
  [deleted]
vfrbgt 12y ago
Yes, but that works great when doing it on the spot in your head, and not so on paper where you have the benefit of writing down the steps of ( non-core ) arithmetic algorithms. Common core breaks down when you have to involve writing down the steps due to the size of the operands and there ordinary algorithms shine.
- parfe 12y ago
  No it doesn't break down. The point of common core is to help students understand why. The how is important but learning the rote algorithms are as helpful for understanding as using a calculator.
  - vfrbgt 12y ago
    Do you always downvote when you don't agree with someone? Kinda undermines your "argument".
    - parfe 12y ago
      Are you addressing me specifically? Hn does not give me the option to downvote direct replies to my comments, even if I wanted to. Someone else on this website felt your comment deserved a downvote.
    - vectorpush 12y ago
      HN does not permit one to downvote direct replies to one's own comments, however, even if it did, I don't see how a downvote has any bearing on the merit of one's argument.
  - minot 12y ago
    If they wrote $5.55, they deserve the full credit. I do arithmetic admittedly weirdly in my head. I can't do arithmetic very quickly. When faced with $20 - $14.45, I round up the $14.45 to $15 and subtract from $20. I have $5. Now, I think how much more I still have and that is $0.55. I add them together to get $5.55. If I can write the answer, why would you dock points just because my way of doing this simple math is inefficient?
bane 12y ago
The problem with Common Core is that it phrases questions like yours using weird words and focuses on specific procedures instead of the correct answer (or a range or reasonable answers). So depending on some factors, your question might be answerable with either "about $5" "about $5.50" "$5" "$5.50" or "$5.55". Which one is the one that will get the child a correct mark? No idea. But you can see any number of angry parents posting pictures of they're children's homework grades where "$5.55" is marked wrong even though it's the most correct. Some people will argue that "well the subject was about estimation", well that still leaves the child with 4 possible correct answers, but school being school, only one of them will be counted as "correct" and anything else will be marked wrong. It turns what's normally an error bounded estimation problem with degrees of accuracy into a binary right/wrong problem that looks exactly like arithmetic and is graded like arithmetic, but unless you have the curriculum guide with the answers in it, it's a crap shoot to figure out what the expected "correct" answer is.
- kaitai 12y ago
  Common Core doesn't phrase the questions in weird ways. The standards are clear and don't tell you how to teach. Much of the training around it and essentially all of the curriculum (repackaged old stuff, new section headings on the same crap) is terrible. But that's the corporatization of education and the poor support for professional development of US teachers at work, which we allow to happen regardless of curriculum content. http://www.corestandards.org/Math/ http://www.corestandards.org/Math/
  - bane 12y ago
    Here, you figure out what question #1 is supposed to be about http://roundtheinkwell.files.wordpress.com/2013/10/the-math-test.pdf http://roundtheinkwell.files.wordpress.com/2013/10/the-math-... What the hell is a "number sentence"? What about #12? "What's the related subtraction sentence?" followed by four answers which all use addition. What the hell is a "counter"? Should first graders also learn about incrementers and changing bases, carry bits and overflow flags? "Write a subtraction story..." What? Based on #12 it must be something about addition since subtraction sentences all use addition. These are barely comprehensible to college educated people with multiple degrees. People who are used to math, critical thinking, who speak multiple languages and solve incredibly complex problems in their day-to-day. I've run this by nuclear engineers with multiple PhDs who couldn't pass this test. It's absurd gibberish to a 6 year old. http://www.washingtonpost.com/blogs/answer-sheet/wp/2013/10/31/a-ridiculous-common-core-test-for-first-graders/ http://www.washingtonpost.com/blogs/answer-sheet/wp/2013/10/...
danso 12y ago
I had to look up this allegedly befuddling question, because I assumed the dad was just being a partisan complainer. Here's what came up: http://dailycaller.com/2014/03/16/bizarro-common-core-kindergarten-math-homework-stumps-dad-with-ph-d/ http://dailycaller.com/2014/03/16/bizarro-common-core-kinder... (to save you the clickthrough: it's a single-page question consisting of a simple illustration of a day at the park...the prompt is: "Today in class your child practiced telling subtraction stories. For tonight's homework, your child will tell you 3 subtraction stories using the attached paper"...presumably, the child is supposed to look at the picture and observe, for example, that there are 10 trees and 9 birds, leaving 1 tree empty) I stand corrected in my assumption: that is a bizarre question. I guess it depends on what was taught in class...if the class went over a similar question and walked through examples...then I guess it's a useful exercise...in the same way that I challenge students whom I teach programming to look at a real-life situation and think about how programming applies. Can 5-year-olds think like that? I seriously have no idea...I just came back from visiting my 1-year-nephew who apparently can recognize words in 3 different languages (English, Spanish, Vietnamese) and communicate common phrases (I'm hungry, I'm sorry) in sign language...admittedly, he still craps his own diapers, but still...I've forgotten how early-brain development can be. Side note: Awhile ago, I asked why HN's Google pagerank was so low (something like a 4 or 5) Paul Graham has stated that the robots.txt on HN throttles Google spiders...and yet when I googled "north carolina common core dad"...the parent comment was one of the top search results. I guess HN's pagerank is moving up?
- acdha 12y ago
  Daily Caller is a right-wing activist site, so be careful about anything they claim, particularly when it's an unsourced forward. The big thing to remember is that Common Core doesn't actually dictate the implementation details people commonly complain about. It's possible that a particular state, district or school does something weird but that's like using some horrible enterprise Java monstrosity as an argument that object orientation is a bad concept.
  - bane 12y ago
    > Daily Caller is a right-wing activist site That may be, but this is a bizarre question. The problem and blame seems to keep coming up over and over again is that CC didn't have implementation control. Why not? Why didn't CC go out the door with a gold standard reference implementation publishers could license and a certification program for alternates? The internet is full of crazy examples like this. Questions that will simply drive people away from math on multiple levels.
falcolas 12y ago
What prevents them from learning both ways? When learning math, I learned the normal way, where you do borrowing. Very useful for larger calculations, and quick when you understand the principals. On the other hand, when we discussed money in grade school, we learned the "count up to nearest denomination increments. Was a bit harder to grasp since you have to think in coin denominations, but it's served me well since then at a few retail jobs. Overall, though, the normal form of borrowing math has been more useful in my career than the denomination method. If you can't do normal borrowing math, advanced mathematics is going to be rough on you.
- nemo 12y ago
  "What prevents them from learning both ways?" Nothing at all, in fact they are actually required to learn both ways. The idea that Common Core is replacing borrowing with left-to-right is just part of a reactionary misinformation campaign.

by parfe 12y ago

boobsbr 12y ago

If you calculate your change without borrowing you just did common core math. Borrowing?

trebor 12y ago
The OP may mean calculating from left to right, instead of right to left. One is merely the reverse of the other. EG: $20 - $14.45 = ... $6 ($0.45 excess) $5.60 ($0.05 excess) $5.55 ($0.00 excess) Instead of: $20 - $14.45 = ... $0.05 ($14.50 total) $0.55 ($15.00 total) $5.55 ($20.00 total)
- Practicality 12y ago
  When I learned calculating left to right it sped up so much of my daily arithmetic. I didn't learn to do that until I was 27. I feel like I wasted a lot of time doing it the hard way first.
  - AngrySkillzz 12y ago
    This is what they're trying to do with the Common Core. We should teach everyone these strategies, not just let smart people figure them out for themselves have everyone else be left behind.
    - elpachuco 12y ago
      Hyperbole Much? Left behind from where? Seriously, a couple of parlor tricks are not gonna leave anybody behind. Use a computer and devote your higher cognitive skills for more productive endeavors. Once you know the basics of how to do something you do not need to continue to get better at it if your computer can do it better for you. Learn something else with the saved time. Edit: Quick example: Is like marveling that you can do arithmetic in your head with 100 digit long numbers. Impressive? Yes. Useful? Nope. Is actually less than useful because all that time wasted you could have used it to learn something else.
      - Retra 12y ago
        You're missing the point. Many maths students learn to dislike math because they cannot remember the rules, or they find them frustrating to use. They are often trying to appease the teacher by mimicking the process. Meanwhile, the better students don't bother memorizing the rules, they just focus on solving the problem. Once they see how the problem is solved, those rules either come naturally, or are supplanted by some other process that also works. This is not about parlor tricks, but about creative thinking. How do you determine whether your 'trick' works or not? How do you know if the problem is solved? Most students believe a problem is solved when they get the 'right answer' -- which often includes "doing what they were told." This is NOT how you identify a solution to a problem. The students who are left behind are the ones who never figure this out.
    - debacle 12y ago
      But they don't explain WHY! If they gave the kids even a basic bit of number theory, it would make so much more sense. If they want to teach the methods they are teaching, substitution and algebra need to be part of math from year 1 and commutativity and associativity need to be explained as more than just vocabulary words.
      - sukilot 12y ago
        We tried that in the 70s. It was called New Math. It failed because parents and teachers didn't already know basic number theory. Some students (like me) were in special programs with well trained teachers, and became highly successful STEM professionals.
  - debacle 12y ago
    It's important to be able to do both.
Kallikrates 12y ago
"you can't subtract 5 from 0, so borrow 10 from 4, now its 5 from 10" and so on
parfe 12y ago
Some random gis image. http://i.imgur.com/RvAUuPK.jpg http://i.imgur.com/RvAUuPK.jpg Compare that to how you could solve the problem in your head. .01 + .70 + 6.00 For my example I bet you'd think 5¢ + 50¢ + $5.00 to compute your change.
- parennoob 12y ago
  Firstly, I think you probably mean +0.01 +0.70 +6.00 Also, when you say the +0.01 and +0.70 there, aren't you implicitly borrowing anyway? It's just "easier" borrowing -- you say that 0.09 + 0.01 = 0.10, as opposed to explicitly borrowing the 1 to the second decimal and subtracting the 9. Similarly, you say that 0.30 + 0.70 = 1.00 instead of borrowing the 1 to the first decimal. I can see why this makes mental maths easier, but I don't see that it is any deep conceptual improvement over the borrowing. Is one of the goals of Common Core to improve mental arithmetic? If so, then this makes sense. Otherwise, unless you properly explain why the two are equivalent, and why the other method is faster, it's more like a neat sleight-of-hand trick that might leave kids slightly more confused about why it is "better" than the borrowing method. [Reference: Non-American, non-parent who knows very little about the American education system, but has some friends teaching in it.]
  - deleted 12y ago
    [deleted]
  - parfe 12y ago
    Fixed, thanks. All math solutions will be equivalent. And it isn't a parlour trick. It's teaching kids to think about breaking down problems into smaller units and composing a solution. The rote algorithms work, but training kids to execute an algorithm won't help them understand. The long form subtraction algorithm isn't a skill that carries over to multiplication. Breaking a problem into smaller components, composing a solution, and checking with your original estimate does carry over. And not just multiplication but programming as well.
AngrySkillzz 12y ago
Add 5 cents to get 14.50, add 50 cents to get 15, add 5 dollars to get 20. .05 + .50 + 5 = $5.55. Much easier than "1, carry the 6"
deleted 12y ago
[deleted]

vfrbgt 12y ago

Yes, but that works great when doing it on the spot in your head, and not so on paper where you have the benefit of writing down the steps of ( non-core ) arithmetic algorithms. Common core breaks down when you have to involve writing down the steps due to the size of the operands and there ordinary algorithms shine.

parfe 12y ago
No it doesn't break down. The point of common core is to help students understand why. The how is important but learning the rote algorithms are as helpful for understanding as using a calculator.
- vfrbgt 12y ago
  Do you always downvote when you don't agree with someone? Kinda undermines your "argument".
  - parfe 12y ago
    Are you addressing me specifically? Hn does not give me the option to downvote direct replies to my comments, even if I wanted to. Someone else on this website felt your comment deserved a downvote.
  - vectorpush 12y ago
    HN does not permit one to downvote direct replies to one's own comments, however, even if it did, I don't see how a downvote has any bearing on the merit of one's argument.
- minot 12y ago
  If they wrote $5.55, they deserve the full credit. I do arithmetic admittedly weirdly in my head. I can't do arithmetic very quickly. When faced with $20 - $14.45, I round up the $14.45 to $15 and subtract from $20. I have $5. Now, I think how much more I still have and that is $0.55. I add them together to get $5.55. If I can write the answer, why would you dock points just because my way of doing this simple math is inefficient?

bane 12y ago

The problem with Common Core is that it phrases questions like yours using weird words and focuses on specific procedures instead of the correct answer (or a range or reasonable answers). So depending on some factors, your question might be answerable with either "about $5" "about $5.50" "$5" "$5.50" or "$5.55". Which one is the one that will get the child a correct mark? No idea. But you can see any number of angry parents posting pictures of they're children's homework grades where "$5.55" is marked wrong even though it's the most correct. Some people will argue that "well the subject was about estimation", well that still leaves the child with 4 possible correct answers, but school being school, only one of them will be counted as "correct" and anything else will be marked wrong. It turns what's normally an error bounded estimation problem with degrees of accuracy into a binary right/wrong problem that looks exactly like arithmetic and is graded like arithmetic, but unless you have the curriculum guide with the answers in it, it's a crap shoot to figure out what the expected "correct" answer is.

kaitai 12y ago
Common Core doesn't phrase the questions in weird ways. The standards are clear and don't tell you how to teach. Much of the training around it and essentially all of the curriculum (repackaged old stuff, new section headings on the same crap) is terrible. But that's the corporatization of education and the poor support for professional development of US teachers at work, which we allow to happen regardless of curriculum content. http://www.corestandards.org/Math/ http://www.corestandards.org/Math/
- bane 12y ago
  Here, you figure out what question #1 is supposed to be about http://roundtheinkwell.files.wordpress.com/2013/10/the-math-test.pdf http://roundtheinkwell.files.wordpress.com/2013/10/the-math-... What the hell is a "number sentence"? What about #12? "What's the related subtraction sentence?" followed by four answers which all use addition. What the hell is a "counter"? Should first graders also learn about incrementers and changing bases, carry bits and overflow flags? "Write a subtraction story..." What? Based on #12 it must be something about addition since subtraction sentences all use addition. These are barely comprehensible to college educated people with multiple degrees. People who are used to math, critical thinking, who speak multiple languages and solve incredibly complex problems in their day-to-day. I've run this by nuclear engineers with multiple PhDs who couldn't pass this test. It's absurd gibberish to a 6 year old. http://www.washingtonpost.com/blogs/answer-sheet/wp/2013/10/31/a-ridiculous-common-core-test-for-first-graders/ http://www.washingtonpost.com/blogs/answer-sheet/wp/2013/10/...

danso 12y ago

I had to look up this allegedly befuddling question, because I assumed the dad was just being a partisan complainer. Here's what came up: http://dailycaller.com/2014/03/16/bizarro-common-core-kindergarten-math-homework-stumps-dad-with-ph-d/ http://dailycaller.com/2014/03/16/bizarro-common-core-kinder... (to save you the clickthrough: it's a single-page question consisting of a simple illustration of a day at the park...the prompt is: "Today in class your child practiced telling subtraction stories. For tonight's homework, your child will tell you 3 subtraction stories using the attached paper"...presumably, the child is supposed to look at the picture and observe, for example, that there are 10 trees and 9 birds, leaving 1 tree empty) I stand corrected in my assumption: that is a bizarre question. I guess it depends on what was taught in class...if the class went over a similar question and walked through examples...then I guess it's a useful exercise...in the same way that I challenge students whom I teach programming to look at a real-life situation and think about how programming applies. Can 5-year-olds think like that? I seriously have no idea...I just came back from visiting my 1-year-nephew who apparently can recognize words in 3 different languages (English, Spanish, Vietnamese) and communicate common phrases (I'm hungry, I'm sorry) in sign language...admittedly, he still craps his own diapers, but still...I've forgotten how early-brain development can be. Side note: Awhile ago, I asked why HN's Google pagerank was so low (something like a 4 or 5) Paul Graham has stated that the robots.txt on HN throttles Google spiders...and yet when I googled "north carolina common core dad"...the parent comment was one of the top search results. I guess HN's pagerank is moving up?

acdha 12y ago
Daily Caller is a right-wing activist site, so be careful about anything they claim, particularly when it's an unsourced forward. The big thing to remember is that Common Core doesn't actually dictate the implementation details people commonly complain about. It's possible that a particular state, district or school does something weird but that's like using some horrible enterprise Java monstrosity as an argument that object orientation is a bad concept.
- bane 12y ago
  > Daily Caller is a right-wing activist site That may be, but this is a bizarre question. The problem and blame seems to keep coming up over and over again is that CC didn't have implementation control. Why not? Why didn't CC go out the door with a gold standard reference implementation publishers could license and a certification program for alternates? The internet is full of crazy examples like this. Questions that will simply drive people away from math on multiple levels.

falcolas 12y ago

What prevents them from learning both ways? When learning math, I learned the normal way, where you do borrowing. Very useful for larger calculations, and quick when you understand the principals. On the other hand, when we discussed money in grade school, we learned the "count up to nearest denomination increments. Was a bit harder to grasp since you have to think in coin denominations, but it's served me well since then at a few retail jobs. Overall, though, the normal form of borrowing math has been more useful in my career than the denomination method. If you can't do normal borrowing math, advanced mathematics is going to be rough on you.

nemo 12y ago
"What prevents them from learning both ways?" Nothing at all, in fact they are actually required to learn both ways. The idea that Common Core is replacing borrowing with left-to-right is just part of a reactionary misinformation campaign.