Some questions

I do not understand how the rounding occurs.

First of all is it a floor(x*100)/100 (trunc-like) or a floor(x*100+0.5)/100 (round-like)?

When does it occur? At any operation other than addition?

For example, when computing the taxes for some value, the result is rounded at every segment (where percentage is applied) or only after the summation? When computing T(R*L%), R*L% is rounded before computations or not?

The gross profit for each enterprise (the one we have to compute) is also with only 2 decimals?