Ineed . what are 2 examples of items that weigh less than a ounce, and 2 examples of items of that weigh more than a ton?

Two Things that weigh less than an ounce would be like a paper clip and paper. 
Two things that weigh more than a ton would be fully grown bears or a leather back sea turtle, also known as the biggest turtle in the world (:

Less: aluminum can, paper clip
More: Tractor trailer, elephant.

Rounding decimals is very similar to rounding other numbers. if the hundredths and thousandths places of a decimal is forty-nine or less, they are dropped and the tenths place does not change. for example, rounding 0.843 to the nearest tenth would give 0.8. , your welcome !