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### Carrying and Borrowing

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Date: 01/14/98 at 14:18:13
From: Barbara PArnell
Subject: Addition and subtraction

My son has a problem understanding addition and subtraction when he
has to do regrouping, what I call carrying and borrowing. He can
borrow a number from the tens or hundreds column but then forgets to
add it in the total. I have explained it, but maybe I'm doing it
wrong. Any ideas on how to explain this so that he understands? He is
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Date: 01/15/98 at 09:39:54
From: Doctor Fred
Subject: Re: Addition and subtraction

When I taught this to my son I used money. Get some pennies, dimes,
and dollar bills. We'll ignore the decimal place involved in the
money. Since your son is in 3rd grade that shouldn't bother him.

Consider the problem,

58
+ 265
------

Put 5 dimes and 8 pennies out on the table to represent 58.
Put 2 dollars, 6 dimes and 5 pennies on the table to represent 265.

He should be comfortable with the idea of adding as putting the two
quantities, or piles, together.

Have him notice that we have a lot of pennies, 13 to be exact. We can
trade in 10 of those pennies for a dime. We still have 3 pennies left
so we write the 3 under the first column of the addition. We now have
another dime so we put a 1 above the dimes column.

1
58
+ 265
-----
3

Now let's look at the dimes. We have 12 of them. Again, trade in 10
dimes for a dollar bill. We'll have 2 dimes left. Put a 2 under the
second column of the addition. We also have 1 more dollar than before.
Put a 1 over the "dollars" column.

11
58
+ 265
-----
23

Now, we have 3 dollar bills so we write the 3 at the bottom and we are
done.

11
58
+ 265
-----
323

You can work a lot of examples that way.

I hope that helps.

-Doctor Fred,  The Math Forum
Check out our web site!  http://mathforum.org/dr.math/
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