Excel Multiplication

[Tom]

By paper and pencil:
111,111,111
X 111,111,111
= 12,345,678.987,654,321

By my Excel:
111,111,111 [Cell A1]
111,111,111 [Cell A2]
12,345,678.987,654,300 [=SUM (A1*A2)]

Notice the difference at the end, P & P = 321, Excel =
300; what the problem please?

Thank you,
Tom

 

[Frank Kabel]

Hi
Excel does support only 15 significant digits (your result has 17)

 

[Bernard V Liengme]

Hello Tom,
First point: you do not need SUM, just enter =A1*A2

Now for the problem. Excel (and all computer programs that conform to the
IEEE standard) are limited to precision of 15 digits. So Excel rounds your
answer 12,345,678.987,654,321 to 12,345,678.987,654,300

Not many people need to do arithmetic to any better precision so it is no
big deal.
Bernard