Two or more decimal numbers are said to be equivalent decimals, when they name the same value (or same amount).
For example, the decimals: 0.2 = 0.20 = 0.200 = 0.2000 etc.
Thus by successive addition of zeros after the decimal part of the number after the decimal point means the same number and hence are equivalent.
Therefore, the decimals: 5.3, 5.30, 5.300, 5.3000 etc are all equivalent.