Double points and brainliest answer this is very important for unit test tomorrow for each of these diagrams in the picture (the little bottom resistor part is not in this) we need to calculate the missing current but i don't know how !

Maybe nobody ever mentioned it to you, but it turns out that
current is another one of those things that's always conserved ...
it can't created or destroyed, just like energy and mass. 

The total current in a circuit is always the same, but it can get
split up and travel through different paths for a while.

==>  The total current is just the amount of current
         that's flowing in and out of the battery.

Diagram #1).
The total current coming out of the battery is 15 A.
That current is going to split up when it reaches the resistors.
   Part of it will flow through each resistor, but both of them
   will still add up to  15 A .
You have  9 A  flowing through one resistor.
So the current in the other resistor is  (15 - 9)  =  6 A.

Diagram #2).
The total current coming out of the battery is 10 A.
That current is going to split up when it reaches the resistors.
   Part of it will flow through each resistor, but all of them
   will still add up to  10 A .
You have  2.5 A  through one resistor and  3.5 A through another one.
So the amount left for the last resistor is  (10 - 2.5 - 3.5)  =  4 A.