1. **State the problem:** Hong wants to paint the ceiling of his restaurant, which is a square with side length 55 feet. Each can of paint covers 275 square feet. We need to find how many cans of paint he will need. 2. **Formula for area of a square:** The area $A$ of a square with side length $s$ is given by: $$A = s^2$$ 3. **Calculate the area of the ceiling:** $$A = 55^2 = 3025 \text{ square feet}$$ 4. **Calculate the number of cans needed:** Since each can covers 275 square feet, the number of cans $n$ is: $$n = \frac{\text{Total area}}{\text{Area per can}} = \frac{3025}{275}$$ 5. **Simplify the division:** $$n = 11$$ 6. **Interpretation:** Hong will need 11 cans of paint to cover the ceiling. **Final answer:** 11 cans