### Video Transcript

Column Subtraction of Numbers up to
10,000 with Regrouping

In this video, we’re going to learn
how to use the standard written method to subtract numbers with up to four digits
when we have to regroup. In this example, we’re subtracting
a four-digit number from a four-digit number. And we’ve modeled the number we’re
subtracting from using place value counters.

3,550 has three 1,000s, five 100s,
five 10s, and no ones. And we have to subtract 1,782. When we add or subtract using the
standard written method, we always start in the ones column first. We have a problem. 3,550 has zero in the ones
place. So there’s nothing for us to
subtract from. And we need to take away two
ones. Because zero is less than two,
we’re going to need to regroup. We’re going to need to take a 10
from the tens column. So we need to take one 10 and
exchange it for 10 ones.

So now we’ve got four 10s in the
tens column. And we’ve got enough ones to
subtract from in the ones column. What is 10 take away two? 10 ones take away two ones leaves
us with eight ones. Now we can move into the tens
column to subtract. We’ve got four 10s left, and we
need to subtract eight. Four is less than eight, so we’re
going to need to regroup again. We’re going to need to take 100 and
exchange it for 10 10s. So we’ve got four 100s left, and we
have 14 10s ready to subtract from. What is 14 take away eight? It’s six. We’ve got six 10s left.

Now we can move into the hundreds
column to subtract. We’ve got four 100s, and we need to
subtract seven. We need to regroup again. We need to take 1,000, which leaves
us with two 1,000s, and exchange it for 10 100s. Now we’ve got 14 100s, and we need
to subtract seven. 14 100s take away seven 100s leaves
us with seven 100s.

Finally, we can subtract in the
thousands place. We’ve got two 1,000s left, and we
need to subtract one. Two 1,000s take away one 1,000
leaves us with one 1,000. So 3,550 subtract 1,782 equals
1,768. We had to do a lot of
regrouping.

If the number on the top row of the
calculation is less than the number on the bottom, we have to regroup. In the ones column, we had zero,
which is less than two. We can’t subtract two from zero, so
we had to regroup. The four digit in the tens column
is less than the eight digit in the tens column. So we had to regroup again. And we had the same problem when we
came to subtract in the hundreds place. Four is less than seven. So we regrouped again.

Now that we’ve thought about how to
regroup when we’re subtracting four-digit numbers from four-digit numbers, let’s try
answering some questions.

Find the result of the following
subtraction: 6,882 subtract 4,357.

In this question, we have to use
the standard written method to subtract 4,357 from 6,882. Both of our numbers have four
digits, which means they have a thousands digit, a hundreds digit, a tens digit, and
a ones digit. And we always start by subtracting
in the ones column first.

We could use a place value table
and counters to help us model the number we’re subtracting from. 6,882 has six 1,000s, eight 100s,
eight 10s, and two ones. And we’re going to subtract the
ones first. We’ve got two ones, and we need to
subtract seven. This is a problem because two is
less than seven. We don’t have enough ones to
subtract seven from. We’re going to need to regroup. We need to take one of our tens and
exchange it for 10 ones. Now that we’ve got 12 ones, we can
subtract seven, which leaves us with five ones.

Now we can subtract in the tens
place. We’ve got seven 10s, and we need to
subtract five. Seven 10s take away five 10s leaves
us with two 10s. Now we move into the hundreds
place. What is eight 100s take away three
100s? We’ve got five 100s left. Eight take away three is five. Now what we need to do is subtract
the thousands. We’ve got six 1,000s, and we need
to take away four, which leaves us with two 1,000s. 6,882 subtract 4,357 is 2,525.

Find the result of the following
subtraction: 9,213 subtract 425.

In this question, we have to
subtract using the standard written method. We always start by subtracting in
the ones column. We’ve got three ones, and we need
to subtract five ones. But three is less than five, which
means we’re going to need to regroup. We need to take a 10 and exchange
it for 10 ones. Now we’ve got 13 ones. We can subtract five. 13 take away five leaves us with
eight ones.

Next, we need to subtract in the
tens column. There are no tens, and we need to
subtract two 10s. And since zero is less than two,
we’re going to have to regroup again. We need to take one of our hundreds
and exchange it for 10 10s. So now we have 10 10s, and we need
to take away two. And we know that 10 10s take away
two 10s leaves us with eight 10s.

In the hundreds place, we’ve got
one 100, and we need to subtract four 100s. Again, since one is less than four,
we have to regroup. We need to take 1,000 and exchange
it for 10 100s. Now we’ve got 11 100s. We can subtract four, which leaves
us with seven 100s. Finally, we can subtract the
thousands. There are eight 1,000s and nothing
to subtract, which means we’ve got eight 1,000s left. 9,213 subtract 425 equals
8,788.

Perform the following column
subtraction: 9,201 subtract 2,468.

In this question, we have to
subtract a four-digit number from a four-digit number using the standard written
method. We always start by subtracting in
the ones column. 9,201 has one one, and 2,468 has
eight ones. But one is less than eight. We don’t have enough ones to
subtract eight from. So we need to regroup. So we need to look to the tens
column. But there’s zero in the tens
place. So we need to take a hundred from
the hundreds column and add it to the tens column. So now we have 10 10s. We need to take one of these tens,
so we’ve got nine left now, and exchange it for 10 ones.

Now that we’ve got 11 ones, we can
subtract our eight ones. 11 take away eight is three. Now we can move into the tens
place. We’ve got nine 10s, and we need to
subtract six 10s. Nine take away six leaves us with
three 10s. Moving into the hundreds column,
we’ve got one 100, and we need to take away four 100s. We know that one is less than four,
so we don’t have enough hundreds to subtract from. We’re going to need to exchange
again. We need to take one of our
thousands and exchange it for 10 100s. Now we’ve got 11 100s. We can subtract four. 11 100s take away four 100s leaves
us with seven 100s. Finally, we can subtract in the
thousands column. We’ve got eight 1,000s, and we need
to subtract two 1,000s. And we know that eight take away
two leaves us with six 1,000s. 9,201 subtract 2,468 equals
6,733.

What have we learned in this
video? We’ve learned how to use the
standard written method to subtract numbers with up to four digits when we have to
regroup.