How much charge is on this capacitor?
it has to add up to 100, right?


Wrong.

The problem is incompletely specified, the intital charge on C2 and C3 is not specified. Lets assume it's zero.

Before the swtich is flicked C1 is fully charged. After the switch is flicked, some of that charge moves to C2 and C3.

Since you have the same ammount of charge and a greater total capacitance that means the voltage is reduced and energy is lost.

If the switch is repeatedly moved back and forth more charge is transffered each time and the voltage on C2 and C3 will rise towards the battery voltage.