Learn about Singapore Math: Grade 3a Unit 1 - part 2 Video

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Learn about Singapore Math: Grade 3a Unit 1 - part 2

Learn about Singapore Math: Grade 3a Unit 1 - part 2 Lets’ say I have spent the last week colleting marbles and I have outdone myself. I have several huge bags of marbles and I need to put them into cans to figure out how many marbles I have so let’s start doing it and then we’ll try to see based on looking at the cans how many marbles we have. So let’s say I just start— I know that I have thousands or more than a thousand marbles so I start filling out a thousand cans so what color was our thousand can? It was green. It’s not always going to be green but the examples that I'm doing are thousand cans on green. So let’s say I have a thousand can here and I start pouring the marbles in and it fills up completely all the way. I filled it all the way up and I still have a lot of marbles left in my collection bag. So I’d say, “Well, I probably going to need another thousand can.” So when we get that other thousand can out— so I have another thousand can here. That’s my other thousand can and I start filling that one up and I fill it up and that one also fills up all the way to the rim so you can even say, “Well, how many marbles have I put in the can so far?” well, this is a thousand. So far I filled up 2000 marbles. I’ve already outdone what I did in the previous example if you could think about by how much, right? so, let me write that down. So, this is 1000 can and this is another thousand can, 1000 here. let’s say that I looked in my bag and I even start to fill up another thousand can but it doesn’t fill up all the way so I'm like, “Well, the thousand cans aren’t useful anymore because it doesn’t help me count how many marbles are in the can.” So, I'm done with the thousand cans and now I have to fill up the next smaller can size and that's of course a hundred cans. But before we go there, how many totals of thousand cans have we filled up? Well, 1000 and another thousand so we have filled up 2000 marbles into these two cans, 1000+1000=2000, right? —Or another way to write it, 2000. So now you know because I can tell that I can’t fill up another thousand can, I take out my 100 cans and say I have one here that’s one of my 100 cans and they it also fills up with marble so I definitely have more than a hundred spare after the 2000 so I have more than 2100 marbles you could say. Now, take another 100 can that one fills up as well. These marbles are super small and this level there— that one fills up. And now, take another one. They’re filling up quickly I’ve collected many, many marbles so there’s a ton of marbles in there, not a ton there’s exactly a 100— right it should be a ton— maybe almost a hundred is it done. And then that’s and then I take another can and that one fills up as well I’m impressed, that fills up as well. And then I try to fill up a 5th and so far I filled out 400 cans and I want to fill up a 5th but it doesn’t fill up all the way. So like all well I can’t used a 100 cans anymore I have to go to the next small so I still have several a good number I’ve taken out most of the marbles out my original marble bag but I still have some left and I actually less than a hundred because I can’t fill out another hundred can. So I take out the ten can. But before I do, that let’s forget how many 100 cans we have. Well this is 100 I could just write up a number now, right that’s 100 that’s a 100 can, well you say that’s 100 can, that’s 100 can but this 100 does a number marbles I have, right. So this is going to be a total of how many marbles— how many marbles are in my 400 can? But you could say, “I have 4 cans of a 100 or a 100 times four.” Well anyway, if you look at it, you have 400 cans, 4x a 100. And just a reminder, we did the presentation when we added all up but this we’re still using the place notation, right when you put the 4 in this place that’s 2 to the left that tells you how many 100 cans you are when you go to three to the left that tells you how many thousand cans you have and so I as I said we don’t have, we have less than a hundred marbles left so we go to the 10 cans, and let’s say— so I filled out one and these are relatively small now. So, fill out one of them and I fill out another one of them and I actually fill out two more. Fill out that one and now I try to fill out a 4 to 10 cans but it doesn’t fill up. It’s something so I’m almost— I’ve almost emptied out my original bag. I just have a couple of marbles left and it doesn’t even fill out a 10 can and actually just pour them out and I see that I have six marbles left and they’re going to be small six marbles left. So anyway, we haven’t counted the 10 cans. So, how many do we have? This is 1/10 can. We call this 1/10 that’s a 1/10 can or we could call this 10 marbles. So there’s a couple of ways we could look at them. We could say, “Well, we have three 10 cans or 3/10.” or we could say, “We have 10 + 10 + 10 = 30 marbles.” And so we have a total of— if we just look at those three 10 cans that are full of marbles, we have 30 marbles and then we have the left over. We didn’t have to put this in any cans because we don’t have a can smaller than a 10 can so we just leave this marbles loose and we could just count them directly— don’t take—it’s not too hard to count 6 marbles. And so we just have 6 marbles here. So my question to you is— we did this— I’m organizing at once so that it won’t slip on marbles but also so that I can easily count my marbles and you can imagine. It’s much easier to pour a thousand marbles into a can until it fills than to just count from 1 to a 1000. So, this is helping me count my marbles. So, how many total marbles do I have? Well, I have 2000 cans of marbles so that is 2000 marbles and then I have 400 cans of marbles so that is 400 marbles and this is and I didn’t have three 10 cans. This is another 36 I know my hand writing isn’t perfect that’s as Euro. So, I have 30 marbles from the 10 cans 3 cans of ten that’s 30 marbles and then I have six left over and then we’re going to add them all up and let me add and make my addition sign a neutral color again maybe I will use blue and we get what do we say what’s a short way of writing 2000 + 400 + 30 +6. What we said this place that’s three to the right of the right most place that’s tell us how many thousand marbles we a have. So we have 2000 marbles right. So we have 2000 marbles and that’s of course we’re all the places. So that’s a thousands place then we’re going to have the 100’s place, we have the tens’ place and then we’re going to have the one’s place. So we went three to the left that’s the thousands and that tells us we have 2000 cans, we have 400 cans that four that’s where we get the four from or this four here. That two we got it 2000’s and then this place right here’s tells us how may 10 cans we have. We have three 10 cans and that’s with a I got this that three is that three or this three. And then the right-most base, before we learned about decimals that’s the right’s most base is tells how many extra marbles did we have that didn’t fit in to attend a hundred. You didn’t fill up any of the cans and we have six left over and that’s the one’s place that’s kind of you could call them the free marbles and the way we would read this is 2436 marbles and that’s not too difficult. We could almost read it before adding them together we could have said 2436 marbles. So either way you look at, it’s hopefully not too difficult so actually let’s just do some practice actually reading numbers so I’m going to write number down and then I want you to maybe you want to post it and read it before I write it. So I may write it in a neutral color so I don’t give you all these cues. So let’s I’m just going to write this number down, this is a different example from what I was doing. So let’s say this is a number after resist the temptation to say it as I write it. And so you might want to pause and say it yourself or try to say it because I’m about to do it. Well how do we think about this. Well as we say let’s write it terms of kind of the number of cans we have and maybe the colors will help. This eight number, what does tell us? That tell us how many free marbles we have in this example so we have eight free marbles. If we go one place to the left, we go to the tens’ place. This is the tens’ place, this is let me make sure I’m sure I’m using the tens’ color, the appropriate color for tens’. So this is tens’ and I don’t know if you could read that, that’s tens’. This one is one’s or free marbles but in the tens’ place that tell us how many ten cans we have or how many groups of 10. Well we have nine groups of 10 and the other way is 90 but let me just write that there color code it. If you go one more space I have to tell us how many cans of a hundred we have, I’ll just eight for a 100 because I’m running out of space that tells how many hundred cans we have and then this a further space to the left that tells us how many thousand cans we have. I’ll just write T for thousand. All right and if we wanted to do what is in the previous problem in the reverse we could actually write this as 5000 + 900 + 90 this is nine tens’, 9 x10 = 90 and this is just 8 and we do a neutral color to add them up. So this equals that. So how do we say it, well it’s 5998. Five thousand nine hundred ninety eight, 5-9-9-8 is read is as five thousand nine hundred ninety eight. So almost when you read it out you’re essentially just telling people, 5000 or 5000 cans, nine hundred or nine hundred cans, ninety or nine ten can’s and eight with eight cans I didn’t fill up a ten can. And so similarly let’s do one more. I try to keep my videos less than 10 minutes but when I get excited I just keep going. Let’s do one more and I have to be silent so that mistakenly so here is the number. I want you to say it paused the video and try to say it and maybe you want to expand it out. Draw a can do whatever you need to do this is good practice. So I’m going to do a shortcut well hopefully Paul is now to try it and I assume you just pause it so I will restart it. So let’s start here it’s good to start from the left actually because when you read it, you read from the left and you start with the biggest number of cans first so this was what if you go this three spaces to the left of this first one. This was a thousand place right. This was a thousands so what is that, that’s 6000 and then what is the next place over to the right, well that’s a hundreds place right and you could remember that a 1000 ÷ 10 = 100, there’s different ways to think about it. So that’s hundreds. So we have zero hundreds, interesting. We couldn’t feel after we filled out a 6000 cans we could even fill out a 100 can and so we had a few left over, we go one more space to the write that’s a one and that’s all is a number of 10 cans we have, not tin cans ten cans, so we have one ten can and then this last base what is that, that tells us a number that’s a free marbles, liberated marbles so that’s just the two. So you could write this if one want to 6000 you could say 6000 zero hundred ten two but obviously you probably never heard someone’s talk like that and actually you don’t even if there’s zero or a certain place you don’t even mention it. So the way you say this is you say this is 6000, you don’t say a zero hundred you just say 6000 and then you don’t say ten two, what is 10 +2. Well, 10 + 2 = 12. So you say this is 6012 and marbles but if you were to expand it out it would be six thousand plus ten plus two and obviously the hundred I could write this a zero hundreds there, all right zero times a hundred. Maybe that will be three zero and I had and confusing like that so 6000 plus zero hundred’s plus ten plus two you could say six thousand ten two that doesn’t sound good so people say 6012. And so that might be a little lesson to intuitive but hopefully you get a sense for it. I will see you in the next video.

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Learn about Singapore Math: Grade 3a Unit 1 - part 2

Lets’ say I have spent the last week colleting marbles and I have outdone myself. I have several huge bags of marbles and I need to put them into cans to figure out how many marbles I have so let’s start doing it and then we’ll try to see based on looking at the cans how many marbles we have.

So let’s say I just start— I know that I have thousands or more than a thousand marbles so I start filling out a thousand cans so what color was our thousand can? It was green. It’s not always going to be green but the examples that I'm doing are thousand cans on green.

So let’s say I have a thousand can here and I start pouring the marbles in and it fills up completely all the way. I filled it all the way up and I still have a lot of marbles left in my collection bag. So I’d say, “Well, I probably going to need another thousand can.” So when we get that other thousand can out— so I have another thousand can here. That’s my other thousand can and I start filling that one up and I fill it up and that one also fills up all the way to the rim so you can even say, “Well, how many marbles have I put in the can so far?” well, this is a thousand. So far I filled up 2000 marbles.

I’ve already outdone what I did in the previous example if you could think about by how much, right? so, let me write that down. So, this is 1000 can and this is another thousand can, 1000 here. let’s say that I looked in my bag and I even start to fill up another thousand can but it doesn’t fill up all the way so I'm like, “Well, the thousand cans aren’t useful anymore because it doesn’t help me count how many marbles are in the can.”

So, I'm done with the thousand cans and now I have to fill up the next smaller can size and that's of course a hundred cans. But before we go there, how many totals of thousand cans have we filled up? Well, 1000 and another thousand so we have filled up 2000 marbles into these two cans, 1000+1000=2000, right? —Or another way to write it, 2000.

So now you know because I can tell that I can’t fill up another thousand can, I take out my 100 cans and say I have one here that’s one of my 100 cans and they it also fills up with marble so I definitely have more than a hundred spare after the 2000 so I have more than 2100 marbles you could say.

Now, take another 100 can that one fills up as well. These marbles are super small and this level there— that one fills up. And now, take another one. They’re filling up quickly I’ve collected many, many marbles so there’s a ton of marbles in there, not a ton there’s exactly a 100— right it should be a ton— maybe almost a hundred is it done.

And then that’s and then I take another can and that one fills up as well I’m impressed, that fills up as well. And then I try to fill up a 5th and so far I filled out 400 cans and I want to fill up a 5th but it doesn’t fill up all the way. So like all well I can’t used a 100 cans anymore I have to go to the next small so I still have several a good number I’ve taken out most of the marbles out my original marble bag but I still have some left and I actually less than a hundred because I can’t fill out another hundred can. So I take out the ten can.

But before I do, that let’s forget how many 100 cans we have. Well this is 100 I could just write up a number now, right that’s 100 that’s a 100 can, well you say that’s 100 can, that’s 100 can but this 100 does a number marbles I have, right. So this is going to be a total of how many marbles— how many marbles are in my 400 can? But you could say, “I have 4 cans of a 100 or a 100 times four.” Well anyway, if you look at it, you have 400 cans, 4x a 100.

And just a reminder, we did the presentation when we added all up but this we’re still using the place notation, right when you put the 4 in this place that’s 2 to the left that tells you how many 100 cans you are when you go to three to the left that tells you how many thousand cans you have and so I as I said we don’t have, we have less than a hundred marbles left so we go to the 10 cans, and let’s say— so I filled out one and these are relatively small now.

So, fill out one of them and I fill out another one of them and I actually fill out two more. Fill out that one and now I try to fill out a 4 to 10 cans but it doesn’t fill up. It’s something so I’m almost— I’ve almost emptied out my original bag. I just have a couple of marbles left and it doesn’t even fill out a 10 can and actually just pour them out and I see that I have six marbles left and they’re going to be small six marbles left.

So anyway, we haven’t counted the 10 cans. So, how many do we have? This is 1/10 can. We call this 1/10 that’s a 1/10 can or we could call this 10 marbles. So there’s a couple of ways we could look at them. We could say, “Well, we have three 10 cans or 3/10.” or we could say, “We have 10 + 10 + 10 = 30 marbles.” And so we have a total of— if we just look at those three 10 cans that are full of marbles, we have 30 marbles and then we have the left over. We didn’t have to put this in any cans because we don’t have a can smaller than a 10 can so we just leave this marbles loose and we could just count them directly— don’t take—it’s not too hard to count 6 marbles. And so we just have 6 marbles here.

So my question to you is— we did this— I’m organizing at once so that it won’t slip on marbles but also so that I can easily count my marbles and you can imagine. It’s much easier to pour a thousand marbles into a can until it fills than to just count from 1 to a 1000. So, this is helping me count my marbles. So, how many total marbles do I have?

Well, I have 2000 cans of marbles so that is 2000 marbles and then I have 400 cans of marbles so that is 400 marbles and this is and I didn’t have three 10 cans. This is another 36 I know my hand writing isn’t perfect that’s as Euro.

So, I have 30 marbles from the 10 cans 3 cans of ten that’s 30 marbles and then I have six left over and then we’re going to add them all up and let me add and make my addition sign a neutral color again maybe I will use blue and we get what do we say what’s a short way of writing 2000 + 400 + 30 +6. What we said this place that’s three to the right of the right most place that’s tell us how many thousand marbles we a have.

So we have 2000 marbles right. So we have 2000 marbles and that’s of course we’re all the places. So that’s a thousands place then we’re going to have the 100’s place, we have the tens’ place and then we’re going to have the one’s place. So we went three to the left that’s the thousands and that tells us we have 2000 cans, we have 400 cans that four that’s where we get the four from or this four here. That two we got it 2000’s and then this place right here’s tells us how may 10 cans we have. We have three 10 cans and that’s with a I got this that three is that three or this three.

And then the right-most base, before we learned about decimals that’s the right’s most base is tells how many extra marbles did we have that didn’t fit in to attend a hundred. You didn’t fill up any of the cans and we have six left over and that’s the one’s place that’s kind of you could call them the free marbles and the way we would read this is 2436 marbles and that’s not too difficult.

We could almost read it before adding them together we could have said 2436 marbles. So either way you look at, it’s hopefully not too difficult so actually let’s just do some practice actually reading numbers so I’m going to write number down and then I want you to maybe you want to post it and read it before I write it. So I may write it in a neutral color so I don’t give you all these cues.

So let’s I’m just going to write this number down, this is a different example from what I was doing. So let’s say this is a number after resist the temptation to say it as I write it. And so you might want to pause and say it yourself or try to say it because I’m about to do it. Well how do we think about this. Well as we say let’s write it terms of kind of the number of cans we have and maybe the colors will help.

This eight number, what does tell us? That tell us how many free marbles we have in this example so we have eight free marbles. If we go one place to the left, we go to the tens’ place. This is the tens’ place, this is let me make sure I’m sure I’m using the tens’ color, the appropriate color for tens’. So this is tens’ and I don’t know if you could read that, that’s tens’.

This one is one’s or free marbles but in the tens’ place that tell us how many ten cans we have or how many groups of 10. Well we have nine groups of 10 and the other way is 90 but let me just write that there color code it. If you go one more space I have to tell us how many cans of a hundred we have, I’ll just eight for a 100 because I’m running out of space that tells how many hundred cans we have and then this a further space to the left that tells us how many thousand cans we have. I’ll just write T for thousand.

All right and if we wanted to do what is in the previous problem in the reverse we could actually write this as 5000 + 900 + 90 this is nine tens’, 9 x10 = 90 and this is just 8 and we do a neutral color to add them up. So this equals that. So how do we say it, well it’s 5998. Five thousand nine hundred ninety eight, 5-9-9-8 is read is as five thousand nine hundred ninety eight. So almost when you read it out you’re essentially just telling people, 5000 or 5000 cans, nine hundred or nine hundred cans, ninety or nine ten can’s and eight with eight cans I didn’t fill up a ten can.

And so similarly let’s do one more. I try to keep my videos less than 10 minutes but when I get excited I just keep going. Let’s do one more and I have to be silent so that mistakenly so here is the number. I want you to say it paused the video and try to say it and maybe you want to expand it out. Draw a can do whatever you need to do this is good practice.

So I’m going to do a shortcut well hopefully Paul is now to try it and I assume you just pause it so I will restart it. So let’s start here it’s good to start from the left actually because when you read it, you read from the left and you start with the biggest number of cans first so this was what if you go this three spaces to the left of this first one. This was a thousand place right.

This was a thousands so what is that, that’s 6000 and then what is the next place over to the right, well that’s a hundreds place right and you could remember that a 1000 ÷ 10 = 100, there’s different ways to think about it. So that’s hundreds. So we have zero hundreds, interesting. We couldn’t feel after we filled out a 6000 cans we could even fill out a 100 can and so we had a few left over, we go one more space to the write that’s a one and that’s all is a number of 10 cans we have, not tin cans ten cans, so we have one ten can and then this last base what is that, that tells us a number that’s a free marbles, liberated marbles so that’s just the two.

So you could write this if one want to 6000 you could say 6000 zero hundred ten two but obviously you probably never heard someone’s talk like that and actually you don’t even if there’s zero or a certain place you don’t even mention it. So the way you say this is you say this is 6000, you don’t say a zero hundred you just say 6000 and then you don’t say ten two, what is 10 +2. Well, 10 + 2 = 12. So you say this is 6012 and marbles but if you were to expand it out it would be six thousand plus ten plus two and obviously the hundred I could write this a zero hundreds there, all right zero times a hundred.

Maybe that will be three zero and I had and confusing like that so 6000 plus zero hundred’s plus ten plus two you could say six thousand ten two that doesn’t sound good so people say 6012.

And so that might be a little lesson to intuitive but hopefully you get a sense for it. I will see you in the next video.

Transcription by: Scribe4you Transcription Services