Shivani needs 93 cupcakes for a birthday party. She already has 33 chocolate cupcakes and 33 vanilla cupcakes. How many more cupcakes should Shivani buy?

1. Break Down the Problem

To determine how many more cupcakes Shivani needs, we will:

1. Calculate the total number of cupcakes Shivani already has.
2. Subtract that total from the number of cupcakes she needs.

2. Relevant Concepts

The formula to find the number of additional items needed is: $\text{Needed Cupcakes} = \text{Total Cupcakes Required} - \text{Cupcakes Already Available}$

3. Analysis and Detail

1. Calculate the total cupcakes Shivani has: $\text{Total Cupcakes Available} = \text{Chocolate Cupcakes} + \text{Vanilla Cupcakes} = 33 + 33 = 66$

2. Calculate the number of additional cupcakes needed: $\text{Needed Cupcakes} = 93 - 66 = 27$

4. Verify and Summarize

We have calculated that Shivani has 66 cupcakes and needs a total of 93. Therefore, the number of additional cupcakes she needs to buy is 27.

Final Answer

Shivani should buy 27 more cupcakes.