Equivalent decimals are decimals that represent the same number or amount. Zeros can be added to the right of a decimal number to create equivalent decimals. The document provides examples of equivalent decimals such as 0.3 and 0.30 as well as examples that are not equivalent like 0.9 and 0.09. It also prompts the reader to write two equivalent decimals for given numbers like 6.03, 0.700, and 8.90.