Final answer:
Diego needs to determine how much more sugar is required to reach 3/4 cup for his cookies. By subtracting the amount he has from 3/4 cup using fraction models, we can find the additional amount needed.
Step-by-step explanation:
Diego is measuring sugar for his cookies and needs 3/4 cup, but the amount he currently has isn't specified in the question. Assuming Diego starts with less than 3/4 cup, to determine how much more sugar Diego needs, we subtract the amount he has from 3/4 cup. If, say, he has 1/4 cup, we subtract that from 3/4 cup to find out he needs 1/2 cup more sugar.
Fraction Model Explanation
Using a fraction model, imagine a full cup divided into four equal parts. Each part represents 1/4 cup. If Diego needs 3/4 cup total and already has 1/4 cup, he needs to fill three parts but already has one, so he needs two more parts, which equals 1/2 cup more sugar.