Early math review
Place value example: 25
Sal shows 25 as 2 tens and 5 ones. Created by Sal Khan.
Want to join the conversation?
- does Sal split the numbers up so that people can understand what it really means?(61 votes)
- Yes. To help give you intuition behind the number and place value of numbers.(55 votes)
- So, how did we start grouping by 10's. It couldn't been something like binary, so why tens? Was it because we have 10 fingers?
Please answer in detail!(18 votes)
- It is because we have ten fingers! ancient people would use the different parts of their bodies to count. They would start with their fingers, then toes, then limbs, then head.(7 votes)
- I dont get this(5 votes)
These are 25 sticks. ^
However, these are very hard to count.
To make it easier, we can split them up like this:
||||||||||(group of 10)
||||||||||(another group of 10)
|||||(and an extra 5)
In total, there are 2 groups of ten and 5 ones which cannot be grouped into tens.
The 2 groups of ten represents the two in the tens place. ( 2 5)
The 5 that cannot be grouped into tens represents the 5 in the ones place. (2 5 )
Putting these two together, we get the number 25.
Hope this helps!(24 votes)
- are there infinite ways to repersent place value?(7 votes)
- There is technically infinite if you represent something as .00000001 googleplex to the power of googleplex every number is basically a place value of itself so yes there are(1 vote)
- does 1 plus 1 really equal 2 of is it 11(5 votes)
- It will equal two because if we had 1 apple, and we got another apple, we would have two apples, not eleven(1 vote)
- Wait, so there's Place value example: 25, so where's Place value example: 24?
How does that Work?(5 votes)
- If I am reading your question correctly, you are asking what the place value for 24 is, right?
If you had the number 134, it would go in like this:
Hundreds | Tens | Ones
Because there is 1 in the hundreds place, 3 in the tens place, and 4 in the ones place.
For 24 it would look like this:
Tens | Ones
Because there are 2 tens, and 4 ones.
Let me give you one more example. For the number 397:
Hundreds | Tens | Ones
Here in the hundreds place we see 3. If 2 were there, the number would be 297 instead of 397. In the tens place there is the number 9. That number tells us to say eighty, fifty, thirty, or any other ty number. In this case, the nine in the tens place makes it 90. Finally in the ones place we have 7. This tells you what 0-9 number goes on the end of 397.
I hope this helped you!(1 vote)
- wath is10000000000000000+10000000000000000000000000000000000000000000000000000000000000(4 votes)
- 1e+61 but i don't think anyone would ask you such a calculation as the calculator dont support such numbers also.(2 votes)
- how do we close the viedeo(2 votes)
- Click outside or just tap outside the video. Or use the x button on the video.(5 votes)
- ned help with this video i dont understand it at all(3 votes)
- what about how to average?(2 votes)
Voiceover:What I want to do in this video is think a little bit about what numbers really represent. Let's say someone were to write down the number 25. So what does this really mean? Well the five here, this is in the one's place so it literally represents five ones. And this two right over here, this is in the 10's place, so let me write that down. That's the 10's place, that's the one's place, so this represents two 10s. What do I mean by that? Well another way to write this is this two represents two 10s, just let me write that down. This is equal to two 10s plus five ones. Now what are two 10s? Well that's literally if you can imagine a 10 being a block of 10 things, so you could imagine if this was a 10 right over here. Let me copy and paste this, so copy. So this is going to be the same thing, this is going to be equal to, you have your two 10s, so one 10 and two tens, so you have your two 10s. So that's your two 10s right over there, that really represents 20 plus your five ones. Plus your five ones. Well if this is a one right over here, and I'm just representing it as kind of one vertical bar, five ones are going to look like, your going to have one, two, I think you see where this is going, three, four, and five. And so these are all different ways of representing the same quantity. 25 is two 10s and five ones. This two is in the 10's place, the five is in the one's place. So two 10s plus five ones, so you could then view it as two groups of 10 plus five ones right over here. And what's this going to be the same thing as? Well two groups of 10, this is the same thing as 20 and this over here is equal to five. So once again, all ways to represent 25. You can view this as two 10s plus five ones or you can view this as 20, let me write this down, 25 you could view because this two is two 10s that represents 20 plus the five ones.