Subtraction

1
Subtraction
with regrouping
Dr. Beth McCulloch Vinson Athens State
University PT3 Grant Funding, Summer 2000
2
Lets review subtraction without regrouping.
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Subtraction with regrouping is used when we are
trying to subtract from the ones place and we
need to borrow some from the tens place.
For example, we can take 6 from 8, but we cannot
take away 8 from 6.
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22 - 5
22 take away 5. Can we take 5 ones away from the
2 ones? No. We have to go to the tens place
and regroup.
5
22 - 5
We need to regroup the 2 tens and 2 ones as 1
ten and 12 ones.
6
22 - 5
We regrouped the 2 tens and 2 ones as 1 ten and
12 ones.
7
22 - 5
Now we can take 5 ones away
from 12 ones.
8
22 - 5
17
When we take 5 ones away from 12 ones, it
leaves us with 1 ten and
7 ones.
9
22 take away 5. First, we see that we cannot take
5 away from 2.
1
12
22 - 5
Next, we go to the tens place and regroup 22 as 1
ten and 12 ones.
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Then we subtract 5 from 12. That leaves us with
7 ones.
1
12
22 - 5
Bring down the 1 in the tens place. Our answer
is 17.
7
1
11
The End
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