# Questions about subtraction-Using Singapore 1A

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DS has been moving very smoothly through Singapore 1A. The only thing I sense he's not grasping instinctual is the subtraction and addition of numbers over ten. For addition, I kept trying to teach him the book's method of taking one of of the numbers and using some of the other number to make it ten.

Example: 7 + 8 = ?

What do you need to add to eight to make it ten? Two.

So take two from the seven and add it to eight and make it ten.

What's 7-2? 5.

What's 10 + 5? 15.

So he has a hard time doing that mentally. Same with subtraction. I have to walk him through it again and again.

I showed him a few other ways, like using the abacus, drawing marks and crossing them out.

So my question is this: for the bigger picture of mathematics, how should I continue to work with him? Is grasping the 'making 10" method a great help to more advanced mathematics? Is using the abacus a good way of helping him get it mentally? Any other tricks/manipulatives I can use?

:lurk5:

:bigear:

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I think you're running into a developmental problem. Let him use manipulatives until he is developmentally ready to do the problems in his head. Assuming your sig is correct, he's 5, right? I wouldn't expect a 5 year old to grasp that concept right away. :)

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The make 10 concept is really big in Singapore, it will keep coming up so it's worth making sure he gets it.

Doe he have his own way of doing the problem? I'd give him something like 7 + 8 and talk him through how he does it himself. I like that Singapore gives lots of mental math techiniques but I have found that often my son has his own way of doing it that is valid and for him more intuitive and therefore faster. What I try to do is make sure the he understands the concept of something like making 10. I do that by working a bunch of problems with him orally. I aso have him orally tell me how he'd do it and if it's valid and works, then it's fine. Then if I give him a sheet of mental math problems I tell him he can do them anyway he wants.

If he's doing them all by drawing marks or an abacus, that's going to be tough with Singapore which has a very heavy emphasis on mental math.

Did he memorize the number bonds earlier? If not, you might want to go back and work on those again. The Right Start game Go to the Dump is a great one for emphasizing "make 10" (It's basically go fish but you each pair has to make 10.)

I'd also go back and use lots of maipulatives like blocks or counters or beans or pennies to show him something like 7 + 8 the way Singapore wants him to do it. I typically find that when a concept it tough that getting out the manipulatives and going back to a very concrete approach helps a lot.

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So my question is this: for the bigger picture of mathematics, how should I continue to work with him? Is grasping the 'making 10" method a great help to more advanced mathematics? Is using the abacus a good way of helping him get it mentally? Any other tricks/manipulatives I can use?

It is essential for doing Singapore style math. I see you have Miquon listed in your signature. You haven't done this sort of thing with C Rods?

Bill

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Yes, I agree, he may be just to young to grasp that yet. My 7yo is in Singapore 2A - he has been having trouble with adding/subtracting numbers over 10 also. I have been using Math Mammoth worksheets (Add and Subtract 2A - Blue Series). I have him usually do 2 sheets a day. I stopped Singapore for a while to get this skill honed. I usually use the linking block manipulatives (or legos) to help. I also have math wrap-ups (addition and subtraction) that he likes to do because he can check his own results. He doesn't really like the MM worksheets, but he does them and he's doing a lot better now.

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Yes, I do think that "making a ten" is an important skill. I use counting chips and multilink cubes, based on what it suggested in the Home Instructor's Guide (HIG). Do you use the HIG? I have found it to be indispensable to introducing and explaining the concept.

For your particular problem, I would probably use 7 blue linking cubes and 8 red ones, linked into 2 sticks. Then, I'd break up the 8 red cubes into 3 and 5, and make a "10 stick" out of the 7 blue and 3 red (or more likely, prompt the child to do it). This way, you have the visual of the 10, and of the original parts. Also, before this, I'd make sure the child understands what "a ten" is and that she is comfortable using that term. I would keep working on this until they get it, using different manipulatives. With counting chips, I'd arrange them on the desk in a nice 2x5 array, so that it is easy to visualize the 3 that are missing to make the 10.

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Ok, thanks! He just turned 6 (haven't updated the siggy yet). We were using counters and I will bring them out again and encourage him to use them more. He wouldn't use them unless I was encouraging him but he did get things better when we were using them.

So he just went through the section on Subtraction and is moving into shapes and size comparisons. Should I just play some games and maybe get a few practice worksheets from online somewhere and help him work through it with the manipulatives (abacus, counters, etc?) that way he can get it familiarized.

As for the number bonds, he seemed ok while we were there, but working with him now he does seem a bit fuzzy on the 1-10 bonds. Can I use a regular card deck for Going to the Dump? I saw it demonstrated once at a conference so I know how it works!

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Ok, thanks! He just turned 6 (haven't updated the siggy yet). We were using counters and I will bring them out again and encourage him to use them more. He wouldn't use them unless I was encouraging him but he did get things better when we were using them.

So he just went through the section on Subtraction and is moving into shapes and size comparisons. Should I just play some games and maybe get a few practice worksheets from online somewhere and help him work through it with the manipulatives (abacus, counters, etc?) that way he can get it familiarized.

As for the number bonds, he seemed ok while we were there, but working with him now he does seem a bit fuzzy on the 1-10 bonds. Can I use a regular card deck for Going to the Dump? I saw it demonstrated once at a conference so I know how it works!

Not counters, use Cuisenaire Rods. Have you used any Miquon stuff???

Go to the Dump is great for this.

Bill

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It is essential for doing Singapore style math. I see you have Miquon listed in your signature. You haven't done this sort of thing with C Rods?

Bill

I haven't tried using Miquon with DS1 yet-save for just some play with the rods back when we were first doing it! Maybe this would be a good time to take a break from Singapore and try out Miquon for awhile! I tried using Miquon Orange with DS2, who is 4, but it was just hard to open up and go for me and try to figure out what all I should do and there was just lots of suggestions. I get how it would be helpful but with just getting started with homeschooling it was less hand-holding than I needed! I have the First Grade Diary and Annotations and it's a lot to look through!

Yes, I do think that "making a ten" is an important skill. I use counting chips and multilink cubes, based on what it suggested in the Home Instructor's Guide (HIG). Do you use the HIG? I have found it to be indispensable to introducing and explaining the concept.

For your particular problem, I would probably use 7 blue linking cubes and 8 red ones, linked into 2 sticks. Then, I'd break up the 8 red cubes into 3 and 5, and make a "10 stick" out of the 7 blue and 3 red (or more likely, prompt the child to do it). This way, you have the visual of the 10, and of the original parts. Also, before this, I'd make sure the child understands what "a ten" is and that she is comfortable using that term. I would keep working on this until they get it, using different manipulatives. With counting chips, I'd arrange them on the desk in a nice 2x5 array, so that it is easy to visualize the 3 that are missing to make the 10.

Ahh, that explains it! I haven't been looking at the HIG at all, and I don't have the linking cubes. I will get some, it sounds like it would help with the matter! Thanks!

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I just want to chime in and say that I agree with what the others are saying. Yes, it is a vital concept (THE vital concept for all mental addition and subtraction) so make sure he's got it before moving on. And, also, kids need to be developmentally ready to make manipulations like that in their heads. It's probably just a matter of waiting a few months for his brain to mature a bit. We've run into a wall at that exact place for both my older girls. I just put away Singapore for a while and waited until they were ready. Sometimes I'd have them do a few problems a day with the RightStart Abacus...

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I haven't tried using Miquon with DS1 yet-save for just some play with the rods back when we were first doing it! Maybe this would be a good time to take a break from Singapore and try out Miquon for awhile! I tried using Miquon Orange with DS2, who is 4, but it was just hard to open up and go for me and try to figure out what all I should do and there was just lots of suggestions. I get how it would be helpful but with just getting started with homeschooling it was less hand-holding than I needed! I have the First Grade Diary and Annotations and it's a lot to look through!

We went to Miquon exclusively when my girls were stuck on this concept in Singapore. It worked well for us! Also, I'd say that 4 is probably too young for Miquon usually, but you know your child best! It does take some getting used to when first starting Miquon. I used the Lab Sheet Annotations a lot when we first started in Orange, but hardly use it at all now. You get used to it after a while. And my girls can often just open and go without any instruction.

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I haven't tried using Miquon with DS1 yet-save for just some play with the rods back when we were first doing it! Maybe this would be a good time to take a break from Singapore and try out Miquon for awhile! I tried using Miquon Orange with DS2, who is 4, but it was just hard to open up and go for me and try to figure out what all I should do and there was just lots of suggestions. I get how it would be helpful but with just getting started with homeschooling it was less hand-holding than I needed! I have the First Grade Diary and Annotations and it's a lot to look through!

There would be no better use of you time that to dig into Miquon right now.

This is the magic time. Watch what happens. The comprehension can happen so fast. Once they have "concrete" understanding varying else falls right into place.

Read the Diary. Make it a fast re-though. Get the big picture. Once it "clicks" with you as a method it really is a natural and easy way to make math comprehensible to young children. Get busy!

Bill

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We haven't gotten there yet in Singapore as I've just received those materials. This was actually one of the reasons I picked up Singapore, though. My 5yo would grab a brown and black rod and find out what they made by "trading up" to an orange and whatever. I woukd DEFINITELY recommend some c rods as it is the perfect concrete manipulative.

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DS has been moving very smoothly through Singapore 1A. The only thing I sense he's not grasping instinctual is the subtraction and addition of numbers over ten. For addition, I kept trying to teach him the book's method of taking one of of the numbers and using some of the other number to make it ten.

Example: 7 + 8 = ?

What do you need to add to eight to make it ten? Two.

So take two from the seven and add it to eight and make it ten.

What's 7-2? 5.

What's 10 + 5? 15.

So he has a hard time doing that mentally. Same with subtraction. I have to walk him through it again and again.

I showed him a few other ways, like using the abacus, drawing marks and crossing them out.

So my question is this: for the bigger picture of mathematics, how should I continue to work with him? Is grasping the 'making 10" method a great help to more advanced mathematics? Is using the abacus a good way of helping him get it mentally? Any other tricks/manipulatives I can use?

My son had the same problem with 1A when it got to 8+7. He and I were so frustrated that we had to break for a few months to drill facts within 10, i. e. what plus what make 10? We used R&S Math 1 to do this, but I never fell in love with R&S math even though we love its English.

8+7 is a multi-step math question as you have shown above. The child really needs to know the math facts within 10 before doing this type of questions smoothly. For my younger son, I knew this was coming, so I drilled him at bedtime before he went to sleep. Then when he started 1A, it was very smooth and we didn't have to take the few months' break as I did with my older.

So if anyone plans to use Singapore 1A, I usually give her the warning of what is coming up in the middle of the book. You do need to supplement with some facts drill.

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I really think it is essential to rely heavily on the HIG... Use the activities before you ever look at the textbook or give him a workbook page to do. My 1st grader is at this same point in 1A, and he is actually "getting it" by using money. I give him 8 pennies, and I have 7. He knows he can trade in the 8 pennies plus 2 of my 7 for a dime, so he has a dime and 5 pennies left. Doing this repeatedly has really helped him get the concept of making 10. Plus he really likes playing with money. We write this down on the dry erase folder as we are working - I would write 8+7, then show under the 7 that 2 and 5 bond to make 7. If you did not spend a lot of time learning all the number bonds, I think it would be valuable to spend a week reviewing those first, using something concrete (like linking cubes or whatever). It seems to me that if the child is really understanding the number bonds, subtraction should not be an issue. I would go back now rather than later if you think there is a chance he didn't really master that number bond idea.

Spend as much time as it takes, it will make your life and his so much easier down the road!

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Last year when we did books 1A and 1B, I cut down several egg cartons to make containers with ten holders. Then we fill the appropriate spots with counting chips. It made it easy to move the right number of chips over to fill one carton when adding.

Without looking it up, I assume this idea came out of the HIG. As others have said, doing the concrete exercises and games suggested in the HIG before moving on to the pictures and abstract numbers in the Textbook and Workbook is a big help.

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:iagree: Break out the Miquon.

Anytime I have one of mine adding over a 10 and it doesn't pop right out, I pull out the rods (8+7, for ex) and line them up next to a 10 rod...they visualize what "fits" in that space (10 and a 5), and know it's 15. Eventually, they visualize that 10 without the rods and that's the goal.

Go to the Dump!:iagree:

Dimes and pennies. I have 8 pennies and found 7 more...I want to trade for dimes...

Doing it this way makes place value, regrouping, etc...all so much easier in the long run. Give it time. It's OK to spend an entire math lesson with just the rods...and It's OK to only get through a couple problems b/c you are REALLY exploring how it all works together.

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Did he memorize the number bonds earlier? If not, you might want to go back and work on those again. The Right Start game Go to the Dump is a great one for emphasizing "make 10" (It's basically go fish but you each pair has to make 10.)
:iagree:

Knowing the facts within 10 (not just making 10's) cold will help tremendously. It's hard for a child to hold all the numbers in their head when "making 10's" if they have to work to figure out what's left over after the 10 is made. If this is an issue, I'd work with the C-rods to cement the concept of making 10's while getting those facts mastered.

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We are using MM2 Addition and Subtraction with my 6 year old right now to make sure those facts are down. We also use flashcards and RS games, which DS adores.

Halcyon (who is off to pull out her c-rods from the math bin because we actually haven't used them for a while, and this would be a great time to revisit:blush:)

Edited by Halcyon
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When I hit math snags, I give it a good try, but I don't see the point of souring a child on math, so I move on, and circle back. For some reason, my son did doubles very easily, but not others, so I banked on that. Then we worked on counting and skip counting and moved into 6+6 is 12, so 6+7 which is one more is ONE more: 13.

Return regularly, try out a game or two, try some straight memorization with flash cards, anything you can think of, while moving on in shapes, telling time, measuring, etc.

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