How to put 3.002, 3.02, 3.001 greatest to least

3.02 has the two in the hundreds place which is bigger than the 3.002 where the 2 is in the thousands place. Then to figure out if 3.002 is bigger than 3.001 you can just look and see that 2 is greater than 1 and that they're in the same places.
Thus from greatest to least it goes 3.02, 3.002, 3.001

From greatest to least you would arrange in this order 3.02, 3.002, 3.001.