Pretend you are having a party and you are making a cake. You invite 21 people over but only 14 can attend. Therefore, you have to change your original recipe. The original recipe called for 6 cups of sugar, 3 eggs, 9 cups of flour, and 2 cups of oil. What is the new recipe?

Let's make a ratio!

okay this isn't the elmo show but still, let's start with reducing fractions

14/21 = 2/3 with a factor of 7

Only 2/3 of your "party peeps" can attend, so ...

You only need 2/3 of your recipe!

2/3 of 6 = 4 cups of sugar

2/3 of 3 = 2 eggs

2/3 of 9 = 6 cups of flower

2/3 of 2 = (4/3) cups of oil