175000 / 100 = 1750 this step finds 1% of 175000 1750 x 4.5 = 7875 this step finds 4.5% of 175000 Commission for first house $7875 199000 / 100 = 1990 this step finds 1% of 199000 1990 x 4.5 = 8955 this step finds 4.5% of 199000 Commission for second house $8955 $7875 + $8955 = $16,830