Calculating Commission

How is my part of the commission calculated?  You get 80% of the commission that is paid by the travel supplier at point of sale (when the booking is made). For example, you have booked a cruise that had a commissionable cruise fare of $1800 for two people (port charges & taxes are non-commissionable). If the cruise line pays 15% commission to our agency, to calculate what you get: $1800 x 15% = $270 paid to A & A, and you get 80% of that, so $270 x 80% = $216.00. Your commission on this booking is $216.00.