Before you order a series of decimal values you must first evaluate each value individually and then compare all the values. We would start by looking at the tenths place. The tenths place that has the largest number, is the greater value. There will be many times when two values will have the same exact tenths place. In this case, move to next place value in line which is the hundredths column and evaluate those numbers for each value. If they are the same, move on to the next place value (thousandths). You will continue this on until you have one value great than the one next to it. Once you have compared the values, you would order them least to greatest, unless you are instructed differently.
This collection of worksheets has students compare the relative values of decimal numbers. This really comes down to students understanding the meaning of place values. I would definitely start off by reviewing place value with students and show them that every successive move to the left is a ten times increase and vice versa on the move to the right. We not only have them compare the values of decimals, we also ask them to order the values from least to greatest. Numbers may be a mix of whole numbers, decimals, and fractions. These worksheets provide a variety of opportunities for students to practice of comparing and ordering whole numbers, fractions, and decimals from the tenths to the thousandths.