Question

A recipe calls for 3/8 cup of butter. How much is needed to double the recipe?

Answer 1

Just double the numerator. 3/8 doubled is 6/8 :)

Answer 2

6/8 cups of butter

Answer 3

why do I only double the numerator?

Answer 4

Because the denominator is basically the entire thing. If you doubled both, it would equal out to the same thing as it was before when you simplify it. Think of the denominator as the entire pizza. You want 3 slices out of the 8 so you have 3/8. But you want to double how many slices you eat, so you eat 6 slices out of the 8. Hope that helps :)