By definition, a Decimal number is a number that has a whole part and a fractional part. Both parts are separated by a point called "Decimal point".
In this case, you have the following Decimal numbers given in the exercise:

You can identify that the Decimal number that has the greatest whole number is:

The others numbers have the same Whole number:

So, in order to identify their order from least to greatest, you need to see the digits after the Decimal point.
You can identify that:

(Remember that "<" means "less than")
Then, knowing the above, you can determine that the order of the given numbers from least to greatest, is:

The answer is:
