Trying to calculate distribution percentages - dealing with rounding errors

Diana_Mullenyahoo 

Rounding "errors" of this sort are very common because "the sum of the rounded parts might not equal the rounded whole".

Often, they are simply tolerated.  Most financial reports contain a footnote to the effect of ``numbers might not add up due to rounding``.

One remedy is:

In P1 (first part):  =ROUND(T1*D1%, 0)

In P2:P100 (other parts):  =ROUND($T$1*SUM($D$1:D2)% - SUM($P$1:P1), 0)

Caveat....  Then you might notice an off-by-one error for some values in P2:P100.  That is a necessary consequence.  So, I would still have the footnote (generalized):  ``calculated numbers might differ due to rounding``.

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Diana_Mullenyahoo  wrote:  ``trying to teach myself Excel ``

First, I commend you for learning that we can write D1%, where D1 contains a decimal presentation of a percentage (e.g. 1.23 for 1.23%).

Most people do not know that "%" is an operator that means "divide by 100".

Nevertheless, I would recommend that you have actual percentages in D1 et al.  For example, 1.3636363636% instead of 1.3636363636.  Simply format D1 as Percentage.

Then you can write simply D1 instead of D1% everywhere.

Also, that probably simplifies the calculation in D1, which I presume is of the form =100*A1/$B$1, where B1 is the sum of A1:A100, for example.  The formula can be simply =A1/$B$1, formatted as Percentage.