Reduced Fee for Siblings
If 2 students from the same family attend in the same year (and neither has already attended for 2 years), the fee as otherwise computed is reduced by 1/9th.
Your son and daughter are both accepted to MathPath and let's say by our other fee policies you owe 2 x $4600 = $9200. You may take off (1/9)*9200 = 1022.22. Your final bill is $8177.78.
Now suppose you also pay 3 months early. Then you may take a further reduction of .015 x 8177.78 = 122.67, for a final fee of $8055.11. Or thought of another way, first you take 1.5% off 9200, obtaining 9062, and then you take 1/9th off that. Again, the final fee is $8055.11. (It is a little theorem that these two reductions commute!)
Your twin daughters are admitted and qualify for financial aid.
We tell you that the reduced tuition for each of them is $3150. Your bill at that point is $6300. Taking off 1/9th, your final
bill is $5600.