Heyo!
So, based on what we know, for every 2 teaspoons of vanilla used in the recipe, it is enough to make 24 cupcakes. Kai, however is required to make 96 cupcakes for the school event. This being said, we need to first:
*Multiply 12 by 8:
12 x 8 = 96
Next, you multiply 8 by 2 (2 represents every 24 cupcakes made.
8 x 2 = 16
Hence, he needs a total total of 14 teaspoons of vanilla to add to the vanilla he already has in order to make all 96 cupcakes. Hope this helps!