Ordinal numbers are the numbers that show placement in a sequence or line—written as 1st, 2nd, 3rd, and so on. There can also write as words, including fourth, fifth, and sixth. They are known for having that the end of the number or term. However, st is added to one of the first numbers. These numbers are based on the cardinal numbers, but ordinal numbers are used to refer to when something happened. For example, some people use first, second, and third in an essay to explain when each event occurred. Sometimes, the number placed above items in a line.