Question

A muffin recipe calls for 2/5 tablespoons of vanilla extract for 6 muffins. Arthur is making 18 muffins. How much vanilla extract does he need?

Answer 1

2/5 tablespoons of vanilla extract ... 6 muffins
x tablespoons of vanilla extract = ? ... 18 muffins

If you would like to know how much vanilla extract does he need, you can calculate this using the following steps:

x * 6 = 18 * 2/5
x * 6 = 36/5    /6
x = 36/5 / 6
x = 6/5 = 1 1/5

Result: Arthur will need 1 1/5 tablespoons of vanilla extract for 18 muffins.