Do kids need to understand "borrow and pay back" subtraction (vs regrouping)?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Please do not teach this nonsense of “borrowing & paying back.” What’s best for your kid is to develop a solid conceptual understanding of regrouping in a base ten system. What’s best is for your kid to be a flexible thinker and to pick which strategy is the most efficient to solve the problem in front of them.

For example: If presented with 1002-997=___, the most efficient strategy is NOT to set it up vertically and regroup. The most efficient way to solve this subtraction problem is to simply “add up.” 998-999-1000-1001-1002. The answer is 5.

NP. So what I end up doing for a problem like that is to say, in my head “ok 997 to 1,000 is 3 and then 1,000 to 1,002 is 2, so 3+2=5.” I don’t have a school-aged kid, so I don’t know if that’s how they’re teaching it to kids these days, but it’s definitely how I think about it.

I just quickly recognize that they’re only a few digits apart, and subtract 7 from 12. The answer is 5. It takes two seconds. Maybe less.

I think this thread illustrates the value of schools teaching many strategies now instead of just the “borrowing and carrying” that we learned as kids. Many of us figured out these other strategies on our own, but others did not, so I’m glad the schools teach them now.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:If they understand one way, have them do it that way. This idea that we have to teach a million ways to do the same thing is ridiculous. If your child is presented with a subtraction problems and can repeatedly successfully solve them, it is good. My child also gets confused with multiple strategies.

The only challenge is that without textbooks, I have a hard time assisting my child with the language and methods they are being taught. I was raised on borrowing and carrying, so when I try to explain it that way, we get nowhere.

A million ways is the way to true number literacy. Which is the important part and not being able to do just one kind of problem one way. The way many of us were taught were very limiting. It was procedural and not drilling down to true math understanding. The current way is actually better but harder in the beginning. It leads to better number understanding. It's also the way people were taught a couple generations back and in other countries.

I guarantee you in Asia no one is learning the borrow and pay back method (ex. 72-29 = 7 tens 12 ones minus 3 tens 9 ones/ this is not the standard subtraction algorithm of 6 tens 12 ones minus 2 tens 9 ones.)

This is why math instruction is so awful in this country. There is no added conceptual benefit of learning this method. OP your child doesn't have to learn it and I would discourage my child from using it. I would be really annoyed if they were taught this method.

They absolutely teach multiple strategies such as this in Asia. Research points to understanding these strategies contributes to strong numeracy. “Knowing and Teaching Elementary Mathematics: Teachers' Understandng Fundamental Mathematics in China and the United States“ focuses on the some of these differences, if you’re interested in actually learning about mathematics education instead of flinging inaccuracies into the void.

[Anonymous]

My child switched from no particular math curriculum, or a loose regurgitation of Investigations (which was abysmal) to Singapore Math in 4th grade (school-wide curriculum). This topic (borrow/carry or regroup) reduced my child to tears in public school, and there was a major fight between teachers about how to teach the regrouping concept, which certainly didn’t help matters.

I’m not a math educator, but maybe some familiarity with a curriculum like Singapore Math would be helpful at this point, even if only as an adjunct to whatever system your child is currently using. Amazon has some of the workbooks, textbooks, guides and errata. My child had to backtrack a bit (the levels are set to have a/b phases for each grade level, with the b level being equal to the first half of the next grade level).

This point might be a good time to work out whatever issues are afoot — they will be prepping for the road to algebra before you know it. Four years, and a lot of work using Singapore Math probably saved my child’s math education. My child will never be an ace algebra student, but is proficient enough to be really solid in AP Statistics.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:If they understand one way, have them do it that way. This idea that we have to teach a million ways to do the same thing is ridiculous. If your child is presented with a subtraction problems and can repeatedly successfully solve them, it is good. My child also gets confused with multiple strategies.

The only challenge is that without textbooks, I have a hard time assisting my child with the language and methods they are being taught. I was raised on borrowing and carrying, so when I try to explain it that way, we get nowhere.

A million ways is the way to true number literacy. Which is the important part and not being able to do just one kind of problem one way. The way many of us were taught were very limiting. It was procedural and not drilling down to true math understanding. The current way is actually better but harder in the beginning. It leads to better number understanding. It's also the way people were taught a couple generations back and in other countries.

I guarantee you in Asia no one is learning the borrow and pay back method (ex. 72-29 = 7 tens 12 ones minus 3 tens 9 ones/ this is not the standard subtraction algorithm of 6 tens 12 ones minus 2 tens 9 ones.)

This is why math instruction is so awful in this country. There is no added conceptual benefit of learning this method. OP your child doesn't have to learn it and I would discourage my child from using it. I would be really annoyed if they were taught this method.

They absolutely teach multiple strategies such as this in Asia. Research points to understanding these strategies contributes to strong numeracy. “Knowing and Teaching Elementary Mathematics: Teachers' Understandng Fundamental Mathematics in China and the United States“ focuses on the some of these differences, if you’re interested in actually learning about mathematics education instead of flinging inaccuracies into the void.

My DH is from India and I'm pretty sure they do use the borrow and pay back method? Whatever they do, it's different from whatever we learned growing up (I'm 35). He gets very confused by how I learned math. I think the shift in math with the common core was trying to be closer to what they teach in places like India?

[Anonymous]

I asked a very popular math tutoring center director this question and he said as long as a student understands either way but super solid and able to compute quickly, it doesn’t matter which way.

Just pick the one that “clicks” for the student. Once they understand it inside out and can do quick computations, they should be able to understand the other way (but just use the way that works for them day to day.)

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:If they understand one way, have them do it that way. This idea that we have to teach a million ways to do the same thing is ridiculous. If your child is presented with a subtraction problems and can repeatedly successfully solve them, it is good. My child also gets confused with multiple strategies.

The only challenge is that without textbooks, I have a hard time assisting my child with the language and methods they are being taught. I was raised on borrowing and carrying, so when I try to explain it that way, we get nowhere.

A million ways is the way to true number literacy. Which is the important part and not being able to do just one kind of problem one way. The way many of us were taught were very limiting. It was procedural and not drilling down to true math understanding. The current way is actually better but harder in the beginning. It leads to better number understanding. It's also the way people were taught a couple generations back and in other countries.

I guarantee you in Asia no one is learning the borrow and pay back method (ex. 72-29 = 7 tens 12 ones minus 3 tens 9 ones/ this is not the standard subtraction algorithm of 6 tens 12 ones minus 2 tens 9 ones.)

This is why math instruction is so awful in this country. There is no added conceptual benefit of learning this method. OP your child doesn't have to learn it and I would discourage my child from using it. I would be really annoyed if they were taught this method.

They absolutely teach multiple strategies such as this in Asia. Research points to understanding these strategies contributes to strong numeracy. “Knowing and Teaching Elementary Mathematics: Teachers' Understandng Fundamental Mathematics in China and the United States“ focuses on the some of these differences, if you’re interested in actually learning about mathematics education instead of flinging inaccuracies into the void.

I actually read Liping Ma's book. She cautions against using the term "borrowing". OP's question is whether his child should learn the borrow and pay back method. It doesn't lead to any conceptual understanding of composing and decomposing numbers. There are so many other ways of solving a problem like 72-29 that actually do lead to understanding. Teaching many random ways to solve problems doesn't make for good instructions. It should be well thought out. In China where Ma studied, math teachers teach elementary math. It would help immensely if schools would actually use textbooks and workbooks like in all Asian countries. Parents could see examples of how students are learning to compose and decompose numbers. To make sure my kids learned math well I bought them textbooks and workbooks AND I bought the teacher's guides for Marshall Cavendish Singapore math.

Anyone reading this who wants textbooks and workbooks and teacher's guides go to https://www.singaporemath.com and they have different versions of math textbooks. The newest series is called dimensions math. Here is a link to samples:
https://www.singaporemath.com/math-samples/dimensions-math-pk-8-samples/