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5th grade (2018 edition)
Unit 4: Lesson 11
Regrouping decimal numbersRegrouping whole numbers: 430
Sal regroups 430 five different ways. Created by Sal Khan.
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Beside the five ways Sal wrote "430" in that table, are there any other ways to write it?(11 votes)
who invented place value!(3 votes)
Place value was actually invented by three different cultures. These were the Mayans, the Babylonians, and the Hindus. (so it's not one person, it's a whole culture.)(2 votes)
how do you regroup 430? please help me.(2 votes)
how do you put 29 in 3 different ways?(2 votes)
Well lets see, 2 tens + 9 ones, 1 ten +19 ones, 0 tens + 29 ones(2 votes)
I don't understand can you make an example just like the question to make the example easier instead of doing hundreds to tens. Like after watching the video multiple times this still makes no sense whatsoever to me!(3 votes)
Khan Academy is just a tool to help you learn. Even if you don't understand it here you can still find out somewhere else.(2 votes)
What are the benefits of this kind of calculation? Can I use this to calculate in my head to get faster result?(1 vote)
It helps open you mind up to new problems and new calculations. Are you in High School yet? Because algebra is going to kill you if you don't know this stuff. I had such problems trying to master algebra because I thought I had already learned everything I could in math pretty much so I was prepared. Don't do that. Hope this helps.(3 votes)
- so in this video there doing this 400 into the tens the 30 is 300 and so they are just putting the things in different ways.(1 vote)
I know there is another way right please tell me mr.khan(1 vote)- I’m really lost in all of this its becoming to hard :( ( I’m mean place value)(1 vote)
I don't get this can someone help me(1 vote)
The video is technically showing us different ways to break apart the number 430 by using place value. So if you add the numbers Sal broke up, the final result will be 430.
Hope this helps!!(2 votes)
Video transcript
Fill in the table
with whole numbers to write 430 in
five different ways. So let's think about
this a little bit. We could literally view
this 4 as 4 hundreds. So it's 4 hundreds. And the 3 is in the tens
place, so it's 3 tens. So this is 4
hundreds and 3 tens. But we could rearrange
things a little bit. For example, we might
only have 3 hundreds. So we took a hundred
from the hundreds place, and we could give it
to the tens place. So if you take that hundred
and give it to the tens place, a hundred is 10 tens. So you've got 10 tens, and
then you already had 3 tens. So you're going to have
13 tens right over here. Now, this seems a
little confusing. Remember, this is 430. This is 300 plus 130. That's still 430. Likewise, you could view
this as 200 plus 230. 230 is the same
thing as 23 tens. Same way, you could view
this as 100 plus 330. 33 tens is 330. And finally, you could view
it as 0 hundreds and 43 tens. 43 tens is 430.