Decomposing whole numbers in word form
About this video
Sal finds the number that is the sum of 6 hundred thousands, 90 thousands and 2 tens. He writes each part as a number (600,000, 90,000 and 20), lines up the place values and adds them to get 690,020.
You'll be able to
- write a part like '6 hundred thousands' or '2 tens' as a number.
- see that 90 thousands is the same as 9 ten thousands.
- add parts with place values lined up to build a number like 690,020.
Key words
- place value
- The value a digit has because of its place, like tens, thousands or hundred thousands.
- hundred thousands place
- The sixth place from the right; a 6 there means 600,000.
- ten thousands place
- The fifth place from the right; a 9 there means 90,000.
- sum
- The answer you get when you add numbers together.
Transcript
- [Instructor] We're told, "The sum of 6 hundred thousands, 90 thousands, and 2 tens can be expressed as which number?" Why don't you pause this video, have a go at this, before we do this together. All right, now the way I'm going to approach it is I'm going to think about what each of these parts of the number, how I can write them down just as a number, and then I'm going to add them up.
So if I wanted to write 6 hundred thousands, how would I write that? Well, it would be 6, and let's see, this would be 60 or 6 tens. This would be 6 hundreds. This would be 6 thousands. This would be 60 thousands. This would be 600 thousands. So 6 hundred thousands is this right there.
And next, we have 90 thousands. Well, I can do that same exercise, and I'm going to add it together. So this is going to be plus, actually, let me just write it here first. So 90 thousands is, that's 90. This would be 900. That would be 9,000. That would be 90,000.
Another way to think about it, I have a 9 in the 10 thousands place. So I have 9 ten thousands, which I guess is the same thing as 90 thousands. So it's going to be the 600,000 plus 90,000. And actually, now let me, I'm going to set this up so I can add them together, so I have the place values lined up.
And then I'm going to add to that 2 tens. Well, this is just 2, and if I put one more 0 here, that's 2 tens, or also known as 20. And how do I know, or another way to think about this, I have the 2 in the tens place. So that's 2 tens. So that is going to be 2 tens right over there.
Another way you could think about everything we're doing here is, this first column, that's your one's place. That second column, let me do this in a darker color, that's your tens place. Your third column is your hundreds place. This fourth column is your thousands place.
This is your ten thousands place. And then this one is a hundred thousands place, hundred thousands. So it's 6 hundred thousands and 9 ten thousands, which is the same thing as 90 thousands. And then we have 2 tens. But let's add it all up. And I am going to get, actually, I could keep those place values there.
I have no ones here, so I still have 0 ones. I only have 2 tens amongst all of these numbers, so it's still 2 tens. I have no hundreds, so 0 hundreds. No thousands, 0 thousands. I have 9 ten thousands here, so I'll put a 9 right over there. And I have 6 hundred thousands.
So what I'm left with is this number right over here. And if we look at the choices, that's exactly choice C.
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