The answer is 1.66×10⁶ sheets of paper.
Monument is tall 555 ft. If 1 ft is 12 inches, than monument is tall 555 ft × 12 inches which is 6,660 inches.
Writing paper is approximately 0.004 inches thick.
The question is how many sheets of paper are needed for 6,660 inches tall monument:
6,660 ÷ 0.004 = 1,665,000 = 1.66 × 1,000,000 = 1.66 × 10⁶ sheets of paper.