Marlene only has enough ingredients to make a 1/2 batch of cookies. For the smaller batch, she only needs 2/3 cup of sugar. How much sugar does the recipe for a full batch of cookies call for? Include all your work in your answer.

Answer: 1 and 1/3 cups, or 4/3 cups

If Marlene is only making a half-batch of cookies, and 2/3 is the sugar required for a half-batch, then a full batch of cookies should require twice as much sugar. To calculate this, you can add 2/3 + 2/3, or multiply 2/3 by 2/1. Either way, you get 4/3, which simplifies to the mixed number 1 1/3 or can stay as the improper fraction 4/3.

We know that if you halve a recipe, you must put half of all the ingredients in, so 2/3 is half of the sugar in the full batch.

2/3 * 2 = 4/3 (or 1 1/3) cups