243.875 to the nearest tenth, hundredth, and one.

243.90  tenth 
243.88  hundredth 
235.00  one 

So this is a matter of rounding. A hundredth is two places after the decimal, an tenth is one place after the decimal, and a one has no decimal. Let's  start with the hundredth.

So your number is 243.875. The hundredth is 2 places after the decimal. Since your next number is a five, you will round up. making it 243.88. This is your nearest hundredth.

A tenth is one place after the decimal. Your next number is 7, so you will round up to make the number 243.9. This is your nearest tenth.

A one has no decimal. Your next number is an 8 so you will round up, making the number 244. his is your nearest one.