Price Variance. Definition: Price variance is the actual unit cost of a purchased item, minus its standard cost, multiplied by the quantity of actual units purchased. The price variance formula is: (Actual cost incurred-standard cost) x Actual quantity of units purchased. = Price variance. If the actual cost incurred is lower than the standard cost, this is considered a favorable price variance.
Calcium carbonate is a common, naturally occurring calcium salt that is often used as a source of calcium in supplements. Its abundance in nature makes calcium carbonate the least expensive supplemental calcium salt. It is also a major component of some types of stone that are used in architecture and sculpture.
Occurrence, properties, and uses. 1  Calcium does not occur naturally in the free state, but compounds of the element are widely distributed. One calcium compound, lime (calcium oxide, CaO) was extensively used by the ancients.