Calculations should NOT be done at the table level, they should be done in a query.
If you have a table with fields NumberInFullCase (as long integer) and FullUnitCaseCost (as Currency), then create a query
Code:
SELECT tblCurrencyCalc.NumberInFullCase, tblCurrencyCalc.FullUnitCaseCost, [NumberInFullCase]/[FullUnitCaseCost] AS PieceCost
FROM tblCurrencyCalc;
(change tblCurrencyCalc to the name of your table)
the result is 0.209045454545455.
With Rounding
Code:
SELECT tblCurrencyCalc.NumberInFullCase, tblCurrencyCalc.FullUnitCaseCost, Round([FullUnitCaseCost]/[NumberInFullCase],2) AS PieceCost
FROM tblCurrencyCalc;
the result is 0.21
You can format the value in a control on a form/report the way you want. (Currency)