Chapters
People often confuse ordinal numbers with cardinal numbers and that is why it is necessary to understand the difference between both numbers as well as understand where cardinal numbers are important and where ordinal numbers are important.
Cardinal Numbers
Cardinal numbers tell us the exact quantity of anything. In simple words, if you look at any object and have a question, "How many?", the answer will be in cardinal numbers. For example, let's say you have five marbles, the value five will be the cardinal number because you are telling the quantity of the object (which is the marble in this scenario).
Ordinal Numbers
Ordinal numbers are the opposite of cardinal numbers. Cardinal numbers describe the quantity of the object, on the other hand, ordinal numbers tell the position of the object. For example, you parked a car in the parking lot. When you came back, you see four more cars in the same row where you parked your car. Now you will try to remember the position of the car. Let's say you parked the car in the fifth row, hence the value fifth is the ordinal number, and the value four is the cardinal number. A few more examples, fourth year, first floor, tenth color, four-hundredth row, etc.
first | eleventh | tenth | one hundredth |
second | twelfth | twentieth | two hundredth |
third | thirteenth | thirtieth | three hundredth |
fourth | fourteenth | fortieth | four hundredth |
fifth | fifteenth | fiftieth | five hundredth |
sixth | sixteenth | sixtieth | six hundredth |
seventh | seventeenth | seventieth | seven hundredth |
eighth | eighteenth | eightieth | eight hundredth |
ninth | nineteenth | ninetieth | nine hundredth |
thousandth | ten thousandth | hundred thousandth | millionth |
twenty-first | thirty-first | forty-first |
twenty-second | thirty-second | forty-second |
twenty-third | thirty-third | forty-third |
twenty-fourth | thirty-fourth | forty-fourth |
twenty-fifth | thirty-fifth | forty-fifth |
twenty-sixth | thirty-sixth | forty-sixth |
twenty-seventh | thirty-seventh | forty-seventh |
twenty-eighth | thirty-eighth | forty-eighth |
twenty-ninth | thirty-ninth | forty-ninth |








first
eleventh
tenth
one hundredth
second
twelfth
twentieth
two hundredth
third
thirteenth
thirtieth
three hundredth
fourth
fourteenth
fortieth
four hundredth
fifth
fifteenth
fiftieth
five hundredth
sixth
sixteenth
sixtieth
six hundredth
seventh
seventeenth
seventieth
seven hundredth
eighth
eighteenth
eightieth
eight hundredth
ninth
nineteenth
ninetieth
nine hundredth
thousandth
hundred
millionth
twenty-first
forty-first
twenty-second
forty-second
twenty-third
forty-
twenty-fourth
forty-
twenty-fifth
forty-
twenty-sixth
forty-
twenty-seventh
forty-
twenty-eighth
forty-
twenty-ninth
forty-
I’m afraid this article (on cardinal numbers) has an unfortunate error. Zero must be considered a cardinal number. The definition of a cardinal number given by the Penguin Dictionary of Mathematics is “A number that indicates the number of elements in a set.” It also defines a null set or empty set containing no elements. The cardinality of this set is 0.