ScoutTN Posted February 7, 2013 Posted February 7, 2013 I realized today that the book is not going to teach the traditional algorithm, from the right. I am confused. Do lots of people do all their subtraction from the left? I find the notation and the thinking pattern difficult. Should I teach what the book has or go with what I understand better? Or do both? If you are a RS C veteran, what did you do? Do Singapore and MM also teach it this way? Quote
PeterPan Posted February 7, 2013 Posted February 7, 2013 This is the best thing in level C!!!! Definitely do it the RS way. Dr. Cotter's research found that many mature, mathematically thinking adults did subtraction from the left anyway, so you're just getting them to that point sooner. There's absolutely no reason to prefer going from the right, and it makes them more prone to errors. You've sucked it up this far. Just do it and trust 'em. It's worth doing that way. :) Quote
Aloha2U Posted February 7, 2013 Posted February 7, 2013 This is the best thing in level C!!!! Definitely do it the RS way. Dr. Cotter's research found that many mature, mathematically thinking adults did subtraction from the left anyway, so you're just getting them to that point sooner. There's absolutely no reason to prefer going from the right, and it makes them more prone to errors. You've sucked it up this far. Just do it and trust 'em. It's worth doing that way. :) I agree! :) ETA: On a side note, and just in case anyone is interested, RightStart will be releasing second (revised) editions - aligned with common core standards, easier to follow format - starting with Level A in March. Quote
Catherine Posted February 7, 2013 Posted February 7, 2013 Definitely go with it. We are through most of level G now and I think it's fine. I am continually impressed with my son's deep grasp of concepts. And we came to RS because he HATED math and was terrible at it. He's now on grade level, pulling ahead and may even be ready for Algebra by eighth grade. RS's emphasis on conceptual understanding, combined with the games for drill, has worked wonderfully for us. Quote
Missouri Okie Posted February 7, 2013 Posted February 7, 2013 This is timely. I was wondering the same thing as the OP. I've gone with it, and my 8 yo son seems to be catching on. But, the left to right thing definitely threw me for a loop! Quote
misty.warden Posted February 7, 2013 Posted February 7, 2013 Do they do that to prevent you from having to borrow? I know all the extra little numbers trip people up sometimes but I would hate doing the extra steps that LtoR requires. I would make sure to teach it both ways just in case. Quote
crazyforlatin Posted February 7, 2013 Posted February 7, 2013 Left to right subtraction is about the only way to do mental math. I've never heard DD doing her math from right to left. Quote
briansmama Posted February 7, 2013 Posted February 7, 2013 Scout, have you looked at Khan Academy? To prepare teaching my ds how to borrow, I watched the Khan video that introduces the concept and he breaks down the different ways to subtract large numbers that require borrowing. One of the ways he demonstrates is by going left to right and it made a lot of sense (even though I didn't learn that way either). Quote
PeterPan Posted February 7, 2013 Posted February 7, 2013 I agree! :) ETA: On a side note, and just in case anyone is interested, RightStart will be releasing second (revised) editions - aligned with common core standards, easier to follow format - starting with Level A in March. Ok, what's going to change if they're trying to align with common core standards? That's cool though, because I'm looking forward to buying level A for ds for this fall. I'll definitely want the new edition. I sold mine off after dd (when I had no hope of ds) and was HEARTBROKEN. We've been doing the Saxon K5 this year, which is really about right for him. I'll take him into RS A after this. So now I'm just curious as to what is changing... Quote
Catherine Posted February 7, 2013 Posted February 7, 2013 Yes, to expand on this, mental subtraction requires a deep grasp of place value. One goal of RS is for the child to be able to mentally calculate most operations with two-digit numbers. It is much quicker than writing, and less vulnerable to errors. For my ds, who has some writing issues, mental calculation did not come naturally, but once he had learned it, there was no stopping him. He mentally multiplies fractions, mixed numbers, and decimals. He can add and subtract consistently with few errors. When he writes the numbers down, he is far more likely to make a mistake. So the left-to-right subtraction is part of that. But there is no need to explicitly teach right to left-the student will understand it without needing to be taught. Ds still does left to right because it is easier for him. This would be a good place for me to insert a plug for Knowing and Teaching Elementary Mathematics by Liping Ma. If you haven't read it, you don't know yet why you had so much trouble learning math as a child. You'll know when you read this book. It's because, in a nutshell, American teachers and American math books are not good at engendering a deep understanding of elementary math. RS does this well. Quote
ScoutTN Posted February 7, 2013 Author Posted February 7, 2013 Thanks, all. I appreciate the encouragement! The unanimous vote for L to R gives me hope. I have read Liping Ma (which is part of why I chose RS!) and will check out the Khan videos. I think I'll give DD a day to just do CWP and play RS games and I'll spend some of the weekend on subtraction L to R so I'm ready to teach Monday. This is only subtraction and I'm confused... Glad DH will take over math when they hit algebra! Quote
kiana Posted February 7, 2013 Posted February 7, 2013 I think I'll give DD a day to just do CWP and play RS games and I'll spend some of the weekend on subtraction L to R so I'm ready to teach Monday. This is an excellent, excellent idea. On a side note, I recommend that you especially look at what happens with problems like 3947 - 3928 (where the two numbers are very close) using L to R subtraction. (just for yourself, and to see why it's useful) Quote
Aloha2U Posted February 7, 2013 Posted February 7, 2013 This would be a good place for me to insert a plug for Knowing and Teaching Elementary Mathematics by Liping Ma. If you haven't read it, you don't know yet why you had so much trouble learning math as a child. You'll know when you read this book. It's because, in a nutshell, American teachers and American math books are not good at engendering a deep understanding of elementary math. RS does this well. I agree. Liping Ma's book is definitely a worthwhile read. It opened my eyes to regrouping - composing and decomposing - not borrowing, which is incorrect. Another worthwhile read through, and nice to have as a reference, is Elementary Mathematics for Teachers. Ok, what's going to change if they're trying to align with common core standards? That's cool though, because I'm looking forward to buying level A for ds for this fall. I'll definitely want the new edition. I sold mine off after dd (when I had no hope of ds) and was HEARTBROKEN. We've been doing the Saxon K5 this year, which is really about right for him. I'll take him into RS A after this. So now I'm just curious as to what is changing... I received an email notification about the second edition last Friday. - New Research and Ideas - Alligned With Common Core Standards - Easier to follow Format - Same Hands On Approach I called and spoke to Kathleen. It is my understanding that the content of each level will be much the same, however, they are adding (some weights and such, in the earlier levels) and organizing material so that it will be covered for those living in states with required testing. Estimated release of second editions: Level A - March 2013 Level B - Late fall 2013 Levels C-F - in 2014 and 2015 The first and second editions are not easily compatible, so it seems that those who are heading into Level C or beyond will want to continue with the first edition, but those just starting will have an option of Level A or B in the second edition. There will be some sample lesson views in a few weeks. I've already read mixed feelings about this, but the good news is that there are no plans to phase out the first editions. Yay! :) Quote
ScoutTN Posted February 7, 2013 Author Posted February 7, 2013 I received an email notification about the second edition last Friday. - New Research and Ideas - Alligned With Common Core Standards - Easier to follow Format - Same Hands On Approach I called and spoke to Kathleen. It is my understanding that the content of each level will be much the same, however, they are adding (some weights and such, in the earlier levels) and organizing material so that it will be covered for those living in states with required testing. Estimated release of second editions: Level A - March 2013 Level B - Late fall 2013 Levels C-F - in 2014 and 2015 The first and second editions are not easily compatible, so it seems that those who are heading into Level C or beyond will want to continue with the first edition, but those just starting will have an option of Level A or B in the second edition. There will be some sample lesson views in a few weeks. I've already read mixed feelings about this, but the good news is that there are no plans to phase out the first editions. Yay! :) Thanks for the info! Quote
ladydusk Posted February 8, 2013 Posted February 8, 2013 Scout, MEP Y2 teaches it that way, too. Maybe a good supplement? around lesson 56 is where they start teaching it. Quote
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