Current time:0:00Total duration:5:20

0 energy points

# Writing a number in expanded form

Sal writes 14,897 in expanded form. Created by Sal Khan and Monterey Institute for Technology and Education.

Video transcript

Write 14,897 in expanded form. Let me just rewrite the number,
and I'll color code it, and that way, we can keep
track of our digits. So we have 14,000. I don't have to write
it-- well, let me write it that big. 14,000, 800, and 97-- I already
used the blue; maybe I should use yellow--
in expanded form. So let's think about
what place each of these digits are in. This right here, the 7,
is in the ones place. The 9 is in the tens place. This literally represents 9
tens, and we're going to see this in a second. This literally represents
7 ones. The 8 is in the hundreds
place. The 4 is in the thousands
place. It literally represents 4,000. And then the 1 is in the
ten-thousands place. And you see, every time you move
to the left, you move one place to the left, you're
multiplying by 10. Ones place, tens place, hundreds
place, thousands place, ten-thousands place. Now let's think about what
that really means. If this 1 is in the
ten-thousands place, that means that it literally
represents-- I want to do this in a way that my arrows
don't get mixed up. Actually, let me start
at the other end. Let me start with what
the 7 represents. The 7 literally represents
7 ones. Or another way to think about
it, you could say it represents 7 times 1. All of these are equivalent. They represent 7 ones. Now let's think about the 9. That's why I'm doing it from the
right, so that the arrows don't have to cross
each other. So what does the 9 represent? It represents 9 tens. You could literally imagine
you have 9 actual tens. You could have a 10, plus
a 10, plus a 10. Do that nine times. That's literally what it
represents: 9 actual tens. 9 tens, or you could say it's
the same thing as 9 times 10, or 90, either way you want
to think about it. So let me write all
the different ways to think about it. It represents all of these
things: 9 tens, or 9 times 10, or 90. So then we have our 8. Our 8 represents-- we see it's
in the hundreds place. It represents 8 hundreds. Or you could view that as being
equivalent to 8 times 100-- a hundred, not
a thousand-- 8 times 100, or 800. That 8 literally represents
8 hundreds, 800. And then the 4. I think you get the idea here. This represents the
thousands place. It represents 4 thousands, which
is the same thing as 4 times 1,000, which is the
same thing as 4,000. 4,000 is the same thing
as 4 thousands. Add it up. And then finally, we have this
1, which is sitting in the ten-thousands place, so it
literally represents 1 ten-thousand. You can imagine if these were
chips, kind of poker chips, that would represent one of the
blue poker chips and each blue poker chip represents
10,000. I don't know if that
helps you or not. And 1 ten-thousand is the same
thing as 1 times 10,000 which is the same thing as 10,000. So when they ask us to write it
in expanded form, we could write 14,897 literally as the
sum of these numbers, of its components, or we could
write it as the sum of these numbers. Actually, let me write this. This top 7 times 1 is
just equal to 7. So 14,897 is the same thing as
10,000 plus 4,000 plus 800 plus 90 plus 7. So you could consider this
expanded form, or you could use this version of it, or you
could say this the same thing as 1 times 10,000, depending on
what people consider to be expanded form-- plus 4 times
1,000 plus 8 times 100 plus 9 times 10 plus 7 times 1. I'll scroll to the right
a little bit. So either of these could be
considered expanded form.