The standard form of a number is the number form you are used to seeing (that is opposed to the word form or expanded form). The ones digit is the one all the way to the right if there is no decimal point. If there is a decimal point, it is the number to the left of the decimal point.
In elementary school, we teach it as an "HTO" chart. H=Hundreds, T=Tens, O=Ones. The HTO shows the order in which they appear. The ones place is all the way to the right, tens in the middle, hundreds all the way to the left. Of course, place value extends far beyond just ones, tens, and hundreds...but I thought this example might at least help you with remembering basic place value a.k.a. the ones place. :)