To answer this question, let us try to analyze the problem. Given that the recipe calls for 1/2 teaspoon of vanilla extract, one recipe will not be enough for the whole class. Since Starla will multiply the recipe by 4, this would also mean that she would have to multiply the vanilla extract by 4 too, making it a total of 2 teaspoons. So the answer for this is that, she will need more than 1/2 teaspoon. Hope this answer helps.
