Answer:
She should have multiplied by 10,000
Step-by-step explanation:
Given table:

To find the conversion rate:

Therefore, 1 hectogram = 10,000 centigrams
So when converting hectograms to centigrams, multiply the mass by 10,000.
⇒ 50 hg × 10,000 = 500,000 centigrams
Rachel's error was that she should have multiplied by 10,000.