What does the "e" value mean?

L

L.C.

Hi sometimes when computing my results i get a number that looks like
"3.123423e-007" in my cell.
what does the "e-007" mean?
 
R

Ron Coderre

First, I think you mean:
3.123423e-07

That is a number in scientific notation, meaning:
1 digit to the left of the decimal point
as many digits as necessary to the right of the decimal
followed by the letter "e"
and an exponent to tell you where the decimal point *should be*

In your case, the actual number is:
0.0000003123423

You'll see that number if you set the number format to anything other than
General or Scientific and set the decimal places to 13.

Does that help?

***********
Regards,
Ron
 
D

Dave Peterson

E-007 is engineering notation (or scientific notation??).

It means to take that first number (3.123423 in your sample) and multiply it by
10^-7 (and 10 raised to a negative 7 means to divide (this time by 1000000).

So your sample is a very small number: 0.0000003123423

7E5 = 7*(10^5) = 7*100,000 = 700,000

3E-2 = 3*(10^-2) = 3*(1/100) = 3/100 = .03

You can play around with this by changing the format
format|cells|number tab|Number category
Show as many decimals as you need--you can see it in the sample box.
 
D

Dave Peterson

A search of Google showed this:

In scientific notation, the numeric part must be at least 1.0 and less
than 10.0, and the exponent can be any integer.

In engineering notation, on the other hand, the exponent must be a
multiple of 3. To accommodate this extra restriction on the exponent,
the numeric part has more freedom: it must be at least 1.0 and less
than 1000.0. That is, you can have 1 to 3 digits to the left of the
decimal point.

http://mathforum.org/library/drmath/view/55606.html

Just for the pedants out there!
 
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