Sunday

September 21, 2014

September 21, 2014

Posted by **zeke** on Sunday, January 7, 2007 at 10:14am.

Let's use this addition problem as an example.

21

35

___

First you add 1 + 5. To check your work, add up, 5 + 1.

If you have a column of numbers and you go down each column to add them together, that's normal, right?

36

95

146

To check to make sure you're right, you'd add

15

95

146

That's called

When my mother was working for her father in the family business (long before calculators or computers) and had to add long columns of numbers, adding down was the standard; then adding up was the double-check.

=)

thank you.

thank you,that was very helpful.

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