4, 2 and 0: Keep 4, 2 and 0 decimal places.

ADD2: 100 becomes 1.00, 10.5 becomes 10.50.

The management department is the invoice tax code.

The usage of "Mu" is as follows:

Price increase calculation:100+100× 5% =105 (100× 5mu =105).

Change rate:100 = 80+80× 25% (100-80 mu = 25)

Price calculation (the cost is 120 and the price is 25% of the profit): the selling price is:

120 ÷ 25mu = 160, and if it is profitable, it will be more than 40 mu (profit).