Singapore's Making a Ten...necessary?

[sweetpea3829]

DS5 is working through Singapore 1A and has reached Unit 6, numbers to 20. He's pretty sharp with mathematics, but this whole concept of making a ten and then adding the singles is tripping him up.

 

Truth be told...I, myself, am not seeing how this method is any quicker than adding it in my head.

 

For example, if I'm adding 8+4, I'll start at 8 and count, in my head, 9-10, 11-12.

 

The Singapore way means I have to remember how many to add to 8 to make a 10 (2), then subtract that from the singles I'm adding (4-2), and then add THAT back to the 10 for the answer of 12. To me, it takes more time!

 

In teaching this method to DS, I'm getting a lot of :blink: from him.

 

Is this method important in the later units in Singapore? Something that he really should have down pat for higher level math? Or can we move on because it's not really that important?

[Halcyon]

Yes, it is essential to the Singapore method.

[black_midori]

I don't use Singapore, but they do the same thing in RightStart & it is (IMO) very important! :)

 

528 + 37

528 + 2 = 530

530 + 30 + 5 = 565

 

Much more efficient to add in your head if you use the "adding 8s" method (add 2 to 8 to make a 10) than if you try to add 528 + 7 + 30 (which, btw, I now automatically add as 528 + 2 + 5 + 30!! lol).

 

I never learned these sorts of methods growing up, and I'm finding that I personally am MUCH faster at mental math now that I have learned (after 2+ years of teaching RS) how to automatically use such methods! :)

[sweetpea3829]

Ok, I never learned these methods either!

 

When I see 528+37, I automatically add 8+7, hold the 5, carry the 1, add it to the 5 I get from 3+2 to make 6, hold the 6 and the 5, bring down the hundreds (5) for 565.

 

So knowing that it's important, we'll continue to plug along and practice with it...lol!

 

The number bonds aspect of it was confusing him, so I set it up like this:

 

8 + 5

+2 -2

___ ___

10 + 3

 

 

I explained to him that we wanted to make the 8 into a ten because tens are easier to add with...so we needed 2 to make that 8 into a 10. But where can we get that 2 from? We take it away from the 5.

 

He's able to go through the motions of doing it, but I don't think he understands conceptually, why we're doing it this way.

 

I'll put that problem, 8+5 on the board and he'll immediately answer...the answer is 13! And then he gets angry when I'm like..."Yes, but...let's work the problem out and see WHY it's 13, and how we get to 13.

 

Many times today, I had to say, "It's NOT about the ANSWER! It's about the PROCESS!!!"

 

GAAAAAH! LOL!

[idnib]

Yes, it's important. It seems longer than adding it in your head because the numbers are small. Later, if he adds 58+74, he'll know that the 8 ones and the 4 ones make a ten + 2 ones left.

[black_midori]

Lol!!!

 

When I first started RS, that was EXACTLY how I added - I lined it up in my mind like a good old-fashioned multi-digit addition problem and added & carried. Like doing large addition problems with a paper and pencil, only doing it in my head! Turns out... that is WAY slower than the methods they teach for mental math in RS (and my understanding is the same basic ones in Singapore)!! It took awhile for me to learn it myself, but once I did I realized that I genuinely can do the math much more efficiently in my head now! :) So, I'd definitely keep on plugging on. I set it up just like you did above - with a +2 and a -2 showing what is going on. It will click soon, I'm sure!

 

I say a lot of that similar thought, too - "Yes, that's the right answer - but you have to be able to show/tell me HOW you got it, step by step!!" :D Mine are 6yo & 8yo.

[TriciaS]

Check out http://www.educationunboxed.com. Her method for teaching that with manipulatives totally opened my daughter's eyes! My dd7 was taught to memorize all addition and subtraction to 20 (and hated math because of that!) while she was in PS, and now she's adding numbers to 100 in her head. The website's method of using an egg carton to "make a ten" is genius.

 

Really, watch those videos! It helps to have a visual/tangible object. Pictures didn't work for my daughter.

[sweetpea3829]

I say a lot of that similar thought, too - "Yes, that's the right answer - but you have to be able to show/tell me HOW you got it, step by step!!" :D Mine are 6yo & 8yo.

 

LOL, mine asks me, "But why?" Well...because I said so!

[sweetpea3829]

Check out http://www.educationunboxed.com. Her method for teaching that with manipulatives totally opened my daughter's eyes! My dd7 was taught to memorize all addition and subtraction to 20 (and hated math because of that!) while she was in PS, and now she's adding numbers to 100 in her head. The website's method of using an egg carton to "make a ten" is genius.

 

Really, watch those videos! It helps to have a visual/tangible object. Pictures didn't work for my daughter.

 

I will definitely watch those videos.

 

When I first introduced the concept, I did actually use egg cartons, lol! He still didn't quite get it, though.

 

I then borrowed from DD6's JUMP Math and gave him a sheet with three ten frames on it. And that seems to be helping, at least with the process.

 

Now...to get him to see conceptually, WHY. I was a bit surprised to hit this snafu with him! He usually picks up on this stuff pretty quickly!

[punchbuggyblue]

Yes! Once you use this method, you won't look back.

There's a book called Knowing and Teaching Elementary Mathematics by Liping Ma. It's awesome at helping North American educated math teachers understand the Asian way of teaching Math.

 

Even the way we name the numbers is different in NA.

In Asian languages 23 is "two tens, three" not twenty three.

and 15 is ten, five

and 535 is 5 hundreds, 3 tens, 5

 

Making tens when grouping is an essential part of understanding the base ten system. Both of my boys can do math calculations in their heads way better than I can, and I attribute it to having started learning their math this way. (Rather than trying to adapt to it, in their 40's!)

 

I highly recommend seeking out the book!

 

Lisa

[TriciaS]

I also used an index card split into 10 spaces, and m&m's, 9 each of two colors.

 

For 7+5, I'd put 7 on the card and ask how many more to make 10? 3, so take 3 from the 5. Now we have 10+2. For some reason, always rephrasing the problem into "now we have 10+_" seemed to help her move the numbers around in her head. I made her say the whole process out loud so many times that she does it whispering to herself now when she's not even really thinking about it! It'll get easier, it's a strange concept at first.

 

6+5=10+1

8+9=10+7

And on, and on, and on...

 

It will become a habit eventually, and then you'll be amazed at the numbers they can add in their head!

[sweetpea3829]

So I watched the video from Education Unboxed...and can I say, that's the FIRST time I've ever seen an abacus being used? LOL!

 

Yes, it's definitely a different way of doing things. Now that I know that it will be important, it'll be easier for me to hide the fact that I'm thinking, "But it's easier if I just do it my own way." LOL!

[swainsonshawk]

I use the al-Abacus to teach this (rightstart math). It makes it effortless. Usually. My daughter is challenging me, though. She wants to count and I won't let her! So she counts on her fingers under the table. I can see it in her eyes, the little sneaky thing!

 

After my first child, I've never taught any of the rest of my kids to count to add--you just make a ten and then the addition part is obvious. That is to say, it was obvious for children 1, 2, and 3. #4 is her own creature. . . .

[redsquirrel]

It seemed clunky to me at first, but it does come in very handy. Now that I am on my second trip through SM, it is second nature.

 

Now, it is the way I do it as well.

[blondeviolin]

I don't use Singapore, but they do the same thing in RightStart & it is (IMO) very important! :)

 

528 + 37

528 + 2 = 530

530 + 30 + 5 = 565

 

Much more efficient to add in your head if you use the "adding 8s" method (add 2 to 8 to make a 10) than if you try to add 528 + 7 + 30 (which, btw, I now automatically add as 528 + 2 + 5 + 30!! lol).

 

I never learned these sorts of methods growing up, and I'm finding that I personally am MUCH faster at mental math now that I have learned (after 2+ years of teaching RS) how to automatically use such methods! :)

 

 

C rods are great visuals here. There are different ways of working mental math with bigger numbers...but it all starts with the ability to make ten. FOr example, in this problem of 528+37=? I would add my hundreds and tens almost instantaneously. BUT, I'd also know that 7 and 8 is beyond ten so I'd have an extra ten. That would leave me with 5 hundreds, 6 tens, and whatever ones I'd have left over from making another ten (5 ones). Either way is valid and efficient.

 

Making ten is actually a great step in understanding place value at an early age.

[Tanikit]

My DD has also just got to this section and we also found it quite long winded to do all that (she wanted to count on) Before I got to that section though I did practice Math facts to 10 and specifically the ones that make 10 and then we also practiced adding tens and ones (10 + 5 = ) etc so that she could see those sums are easier and can be done in her head. The better she has her facts memorised the faster she can do it and the less long winded it seems, however I do not like pushing Math facts at this age, so have done them as games with her and play those games every Friday to reinforce them. Using manipulatives also helped a lot. The other thing that worked with my DD was to give her a home made worksheet and tell her she could do the first one by her method and then had to use "my method" for the rest - at least she felt she had been heard.

Edited September 13, 2012 by Tanikit