Tell the order of things in a set. First, second, third, etc. They DO NOT show quantity. They only show rank or position.
Here are some examples using ordinal numbers: -3rd fastest -6th in line
They are numbers that name something. Example: a telephone number, a player on a team. Nominal numbers do not show quantity or rank. They are used only to identify something.
Here are some examples of nominal numbers:
-jersey number 4 -zip code 02116
The understanding that if the length of object X is equal to (or greater/less than) object Z, then object X is the same length as (or greater/less than) object Z. A child with this understanding can use an object as a referent by which to compare the heights or lengths of other objects.
The mental activity of slicing up an object into the same-sized unit.