Answer:
Positive: Decimals are a part of a whole just like fractions are a part of a whole. Therefore, a positive decimal is always greater than a negative decimal.
Negative: When you have two negative decimals, the one closer to zero is always greater. The farther a negative decimal is from zero, the smaller its value.
All of it put together (same text as above):
Decimals are a part of a whole just like fractions are a part of a whole. Therefore, a positive decimal is ALWAYS greater than a negative decimal. When you have two negative decimals, the one closer to zero is always greater. The farther a negative decimal is from zero, the smaller its value.