They indicate the order of a collection of things within a list. This number tells you the position in a list. i.e. First, Second, Third, etc. If you come third in a race, you are number three in the race. Ordinal numbers are simply “a thing’s position in a series.” (As in, first, second, third, and so on and so forth.) That’s it!! Take turns being the teacher and ask the question in the book.