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## 4th grade

### Course: 4th grade > Unit 1

Lesson 4: Regrouping whole numbers# Adding whole numbers by their place values

CCSS.Math:

Lindsay adds numbers like 19 thousands + 7 tens by thinking about their place values.

## Want to join the conversation?

- would 3 hundreds + 17 tens equal 470?(26 votes)
- yes. it is. 300+100=400+70=470(3 votes)

- no offense but these are too long and non helpful!(21 votes)
- looked at it a few now i think i know how to do this its just looks confusing(20 votes)
- this is easy a little?(8 votes)
- just keep trying until u get it i promise it wont take long(1 vote)

- What is this I don’t understand(6 votes)
- why would the answer be 72,000(5 votes)
- because 22,000 is equal to 20,000+2,000 so 50,000+22,000=72,000(1 vote)

- she keeps on saying literally(5 votes)
- I understood at7:00(4 votes)
- This is very easy on 1 minute 35 seonds(3 votes)
- Everything is easy(2 votes)

- REECE

dosent know how to do this stuff(2 votes)

## Video transcript

- [Voiceover] What is 19
thousands plus seven tens? First let's think about
what are 19 thousands, and what are seven tens, and then from there we can add them. So, 19 thousands, would
quite literally be, if we had a thousand, 19 times. So there's a thousand one time. If we had a thousand two
times, we would have 2000. If we had a thousand three times, we would have 1000, 2000, 3000. And the pattern here
should be pretty clear. If we have 19 thousands,
or a thousand 19 times, we would have 19,000. So, 19 thousands is
literally 19 thousands. And then seven tens, same thing, we could have seven tens. We could have 10 seven times. So, 10 plus another 10, plus another 10, and this one's a little
simpler to do than the 19, we only have to list seven tens this time. That's six tens, and there's seven tens. So, seven tens would be
literally seven tens. Or, 10, 20, 30, 40, 50, 60, 70. So, seven tens is 70. And then if we want to combine these, or add these, we would have 19 thousands, zero hundreds, the seven tens, and zero ones. Or 19,070. We could've also thought
about that question in terms of place value instead of listing out all the thousands, and listing out all the tens, we could have thought of the place values. We had 19 thousands, which
means we want our last digit, the nine, to be in the
thousands place value. And then the other digit, we had one, would go in front of it. So, this is read 19 thousands, and by writing that thousands there, we covered all these empty place values. Or, the three zeros we ended up adding. The thousands can be represented by these three zeros at the end. Whereas, seven tens, we put
a seven in the tens place, and again, we have an empty
place value behind it. We had no ones with it. The tens, by saying tens, we
implied this zero after it. So, the thousands added
these three zeros to the end, and seven tens added one zero to the end. And again, if we combined them, like we saw in the previous one, we'd have 19 thousands, zero
hundreds, and seven tens. So, either way, whether we list out what 19 thousands is
literally with 19 thousands, or seven tens, literally 10 seven times, or we look at it in terms of place value, and add the zeros on the end. Either way, our solution will be 19,070. Here's one more. We have five ten-thousands
plus 22 thousands. So, two ways again we
could try to solve this. One, we could think about
what are five ten-thousands? If we had 10,000 five times, another 10,000, another, that's three. Four ten-thousands,
and five ten-thousands, that would be a total of 50,000. 10,000, 20, 30, 40, 50 thousands. So, five ten-thousands is 50,000. Let's write that up here, 50,000. Plus, 22 thousands. 22 thousands, remember when
we did the 19 thousands, if we wrote one 1000
it would be a thousand. If we wrote a thousand two
times, it would be two thousands. If we wrote it 22 times, then
it would be 22 thousands. There'd be 22 thousands. And we could combine these numbers, 50,000 plus 22,000, will
be a total of 72,000. So, one way there, that
first way we talked about, is to think about what does
five ten-thousands look like, and what do 22 thousands look like, to get our numbers and then add them. Or, the other way that we could solve this is with a place value chart. Is, thinking about place value. So, let's put a place value chart in here, and then put our first number,
which was five ten-thousands. So, we have five in the
ten-thousands place, five ten-thousands. And we can fill in the zeros behind it in these empty place values. There were no thousands,
hundreds, tens, or ones. So, for ten-thousands, we
added four zeros behind it. And the other number was 22,000, so 22. We read this as 22,000,
always saying the place value of the last non-zero digit we see. So, 22 and then thousand. And then, with thousands like before, we'll add three zeros to the end. And finally, when we
combine these numbers, when we look at the place values, we now have seven ten-thousands. We have two thousands. Still no hundreds, no tens, and no ones. So, our solution for five ten-thousands plus
22 thousands is 72,000.