subtraction with regrouping
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Subtraction with Regrouping. Mrs. Walker 4 th Grade. Difference. The answer to a subtraction problem!. 100 – 25 = 75. Inverse Operations. Opposite operations. This means that one operation undoes the other. Example: Addition and Subtraction. 100 – 25 = 75 75 + 25 = 100. - PowerPoint PPT PresentationTRANSCRIPT
Subtraction with Regrouping
Mrs. Walker 4th Grade
DifferenceThe answer to a
subtraction problem!
100 – 25 = 75
Inverse OperationsOpposite operations.
This means that one operation undoes the other.
Example: Addition and Subtraction
100 – 25 = 7575 + 25 = 100
Subtraction Rules
1. When you subtract 0 from any number, the result is the number.
6-0=6 4-0=4
2. When you subtract any number from itself, the result is 0.
6-6=0 5-5=0
7 23 4
You can’t take 4 from 2
so you must regroup the
72.
7 2Let’s just think about the 72 for a minute.
Remember the place
value columns.
tens
ones
Put 72 in expanded form: 70 + 2You can borrow 10 from the 70
and give it to the 2 and still have 72.
7 0 6 0borrow 10 1 2
2 give 10
7 27 2
+ +
Now let’s get back to the original problem.
7 23 4
You can’t take 4 from 2
so you must regroup the
72.
6
\Borrow 1 ten from the 7.
12Give the 1 ten
to the 2 to make 12.
Now subtract.3 8Let’s read the completed problem:
72 – 34 = 38
Remember you’re actually
taking 10 from 70
313Give the 1 ten
to the 3 to make 13.
87
\Borrow 1 ten from the 8.
2 6
You can’t take 6 from 3
so you must regroup the
83.
Now subtract.5 7Let’s read the completed problem:
83 – 26 = 57
Remember you’re actually
taking 10 from 80
Practice in your notes!
• 3,214 - 957=
• 4,275 - 1,345=
• 1,542 – 481 =
• 2,962 – 845 =
Its easy! Follow these steps:
1.1. Line up the decimal points Line up the decimal points and subtract the columns and subtract the columns
from right to left, regrouping from right to left, regrouping as needed.as needed.
2.2. Place a decimal point in the Place a decimal point in the answer directly below the answer directly below the
other decimal points.other decimal points.
Subtraction WordsSubtraction WordsDifference Fewer
How many more How much more
Left Less
Minus Remains
Subtract Were Not
Words ending with “-er”
(higher, longer, faster, heavier, larger, shorter, slower, farther, etc.)
Example: Jean's apple weighs 100 grams, and Karen's apple weighs 80 grams. How much heavier is Jean's apple?
Word Problem Practice:
Mr. Tyson flew 1,224 miles in May and he flew 2,145 miles in June. How many more
miles did he fly in June than in May?
2,145
1,224
921
Is this what you have on your paper?
Now, you write a word problem requiring subtraction to solve it.
-
7 2
Name
6 4 8 3 3 1 6 0 4 2
2 5 7 3 8 2 7 5 2 1 9 3
5 0 7 1 4 3 9 1 2 0 5 2
3 3 6 2 9 4 3 2 4 4 7 0
Directions: For each problem, roll two dice.Write each number you roll in a box then solve.