Subtraction Using an Expanded Method (part 3 of 5)
1.
Subtraction Of Whole Numbers Using An
Expanded Method
(the last step towards using a standard written
method for subtraction)
Part 3 of 5: Subtraction with adjustment from the tens.
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visit: www.makemymathsbetter.com
2.
Subtraction Of Whole Numbers Using An
Expanded Method
(the last step towards using a standard written
method for subtraction)
Part 3 of 5: Subtraction with adjustment from the tens.
It is important that you have already viewed and understood parts 1 & 2
before you go any further.
For more maths help & free games related to this,
visit: www.makemymathsbetter.com
3.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
400
_
70
5
200
20
9
4.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
400
_
70
5
200
20
9
5.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
400
_
60
70
5
200
20
9
6.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
7.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
The calculation can
then be carried out:
400
_
60
70
15
5
200
20
9
8.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
6
Firstly, subtract the units.
9.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
40
6
Followed by the tens
10.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
And finishing with
the hundreds:
60
70
15
5
200
20
9
200
40
6
11.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
The 3 answers are then added together to give the final answer
12.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
4 7 5
_
2 2 9
13.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
6
4 7 5
_
2 2 9
Firstly, an
adjustment is
made from the
tens
14.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
6
15
4 7 5
_
2 2 9
Firstly, an
adjustment is
made from the
tens to the units
15.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
6
15
4 7 5
_
2 2 9
6
Then subtract the
units
16.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
6
15
4 7 5
_
2 2 9
4 6
Followed by the
tens
17.
When subtracting, there will be times when the units in the bigger number are
smaller than the units in the smaller number, e.g. 475 – 229
When this happens, an adjustment is made from the tens to the units.
A ten is effectively taken from the tens column.
And added to the units column.
400
_
60
70
15
5
200
20
9
200 + 40 + 6
=
246
When this can be performed confidently, it can be simplified to a standard
written method:
6
15
4 7 5
_
2 2 9
2 4 6
And finally the
hundreds
18.
That’s it for now......
For more help with your maths, try
my book:
mastering multiplication tables
on amazon.com
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