About this video
A digit's value depends on its place. In 217, the 7 is 7 ones, the 1 is one 10, and the 2 is two hundreds, or 200. The video then compares three numbers to find the one where the 7 is worth 70: 572.
You'll be able to
- say what each digit in a three-digit number is worth.
- find which number has a digit worth a certain value, like a 7 worth 70.
Key words
- digit
- One of the symbols 0 to 9 that we use to write numbers.
- value
- How much a digit is worth because of its place.
- place
- The ones, tens or hundreds spot where a digit sits.
Transcript
- [Narrator] So I'm going to write down a number and I'm going to think about how much do each of these digits of the number, what value do they represent? And actually, let me pick on this two here. What does that two represent? Does it just represent two, or does it represent something different than just two?
Pause the video and think about that. All right, now we'll think about it together. And actually I'm going to start with the seven here. The seven is in the one's place. So this seven represents seven ones, which is of course still just seven. So nothing too surprising there.
Then we could go to the ten's place. So this one doesn't just represent one, it represents one 10. Or another way to think about it, it represents 10. And then this two, it is in the hundred's place. So it doesn't just represent two, it represents two hundreds, we could write it that way, or it represents the value 200.
So the number here is 217. The two represents two hundreds or 200. Now let me give you a slightly different question. I'm going to write down three numbers. So we have this number and I'm intentionally not saying it out loud, that number, I have this number and I have this number.
And what I want you to do is pause the video and tell me in which of these three numbers does the seven represent 70? Pause the video and think about that. All right, now let's work through this together. So let's start with this top number, In this number, the seven is in the one's place, so that seven really just represents seven ones, which is still just seven.
So this seven does not represent 70. Now in this next number, the two is in the one's place and we see that the seven is in the ten's place. So this actually represents seven tens. Well, seven tens is the same thing as 70. So it's actually in this second situation where the seven does represent 70.
This number is 572, the seven represents 70. And let's just check this last number here. Well, here are the seven is not in the one's place, not in the ten's place, it is in the hundred's place. So this represents seven hundreds or 700. And that makes sense, this number here is 705.
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