Subtraction by "Regrouping"
(Also called "borrowing" or "trading")
To subtract numbers with more than one digit:
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write down the larger number first and the smaller number directly below it
making sure to line up the columns!
- then do subtractions one column at a time like this (press play button):
Smaller Number - Bigger Number
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But what if a column has a smaller number on the top?
How do you do 2 - 5 ? |
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The Solution: |
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Make the "2" larger by "regrouping" like this (press play button): |
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In 32:
- the "3" means 3 tens,
- the "2" means 2 units,
So you:
- reduce the 3 by 1
- increase the 2 by 10
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And this is how to do it:
You can use this method whenever a column has a smaller number on top, as in this example:
Zero
But you can't regroup from zero ...
But you can make a "0" into a "10" by regrouping it first, them carry on normally, like this:
Now, you can practice with these Subtraction Worksheets
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