1. **State the problem:** A bakery sold 400 cupcakes in a day, 68% of which were mocha cupcakes. We need to find how many cupcakes were chocolate. 2. **Formula and concept:** The total cupcakes sold is 400. The percentage of mocha cupcakes is 68%, so the percentage of chocolate cupcakes is $100\%-68\%=32\%$. 3. **Calculate the number of chocolate cupcakes:** $$\text{Chocolate cupcakes} = 32\% \times 400 = \frac{32}{100} \times 400$$ 4. **Simplify the multiplication:** $$= \frac{32}{\cancel{100}} \times \cancel{400}$$ $$= 32 \times 4 = 128$$ 5. **Answer:** There were **128 chocolate cupcakes** sold that day. This means out of 400 cupcakes, 128 were chocolate and the rest were mocha.