If you double a recipe that calls for three cups of flour, how many cups do you need?

When you double a recipe, you multiply all the ingredient amounts by two. In this case, the original recipe requires three cups of flour. To find out how much flour is needed when you double it, you perform the multiplication:

3 cups of flour × 2 = 6 cups of flour.

Thus, to properly adjust the recipe, you would need a total of 6 cups of flour. This calculation clearly illustrates the basic principle of scaling recipes, which is straightforward but can sometimes lead to errors if the multiplication step is overlooked.