We explain what ordinal numbers are, how they are written and their differences from cardinal numbers. Also, the ordinal numbers from 1 to 1000.
What are ordinal numbers?
In mathematics, ordinal numbers are those that, instead of indicating the number of things to which one refers, indicate the order of things within a particular sequence or succession. That is, they are the numbers with which we express the order or sequence of things, instead of their quantity.
For example, given any three elements in a sequence 1, 2, 3, we will say that 1 is the first element, 2 is the second and three is the third. These are, precisely, their ordinals, and they differ from the cardinal numbers, with which quantities are expressed in a common way.
Ordinal numbers have their correlation in the language in ordinal adjectives. As such, they are equipped with gender and number, and are usually used in common language up to the tenth (10) or twelfth (12), since from there they become more complicated. It is normal for ordinals above that point to be replaced with cardinal numbers (thus, John XXIII can be said “John twenty-three” instead of “John twenty-third”).
Difference between ordinal numbers and cardinal numbers
Cardinal numbers are natural numbers that are used to express a quantity that is, a certain number of things. For example, when we say that we have five fingers on each hand, we are enumerating them and, therefore, using cardinals to express the total number of fingers counted: five (5) in each hand, ten (10) in total.
However, when it comes to ordering the fingers of the hand and counting them from the thumb to the little finger, we no longer care so much about how many there are, but rather what order they are in. Thus, we can say that the thumb is the first (1st), the index second (2nd), the middle third (3rd), canceling the room (4th) and the little finger fifth (5°), and for this we have turned to ordinal numbers, since they serve to express order and sequence, instead of total quantity.
How are ordinal numbers written?
The ordinal numbers are written using a sign that accompanies them and distinguishes them from the cardinal ones: the degree sign (°). So, for example, the number one (1) becomes the first (1st). It is possible that said symbol will be replaced by a flying letter “a” (to) when it is necessary to distinguish the feminine gender of the referent: first (1to).
On the other hand, ordinal number names are formed through the use of specific suffixes which serve to express a notion of a certain quantity. These suffixes changed a lot throughout the history of the language and that is why today they may seem strange to us. The main suffixes are:
- -ero/was used in the first of the ordinals, as in first (1st) either third (3rd).
- -to/ta the most common of the suffixes among the ordinals, as in fifth (5th) or sixth (6th).
- -eno/ena incorporated into medieval Spanish but lost except in the case of ninth (9th).
- -avo/ava used only for fractional numbers. For example: a fourteenth (1/14).
- –th/th used only for ordinal tens: tenth (10th), twentieth (20°), etc.
In addition, sometimes ordinal adjectives can be abbreviated and for this the cardinal numbers and the suffix corresponding to the ordinal are used, followed by a period. In this case, the gender needs of the referent are also respected. For example: first becomes 1st., second becomes 2nd. and tenth becomes 10th.
On the other hand, there are some exceptions to the use of ordinal adjectives, as in the case of first and thirdwhich when occupying a position next to a noun lose their last vowel: “We caught the first train of the day” and not “the first train of the day”.
How do you convert a cardinal number to an ordinal number?
This transformation is extremely simple: just add the corresponding ordinal sign (°) next to the cardinal number, to convert it into an ordinal. In case we want to write your name, it is enough to learn the corresponding ordinal name.
Ordinal numbers from 1 to 1000
Below we can see the ordinal numbers from 1 to 1000, with their respective names:
| Cardinal number | Ordinal number | Ordinal name (masculine, feminine) |
| 1 | 1st | first, first (sometimes first) |
| 2 | 2nd | second, second |
| 3 | 3rd | third, third (sometimes third) |
| 4 | 4th | fourth, fourth |
| 5 | 5th | fifth, fifth |
| 6 | 6th | sixth, sixth |
| 7 | 7th | seventh, seventh |
| 8 | 8th | eighth, eighth |
| 9 | 9th | ninth, ninth |
| 10 | 10th | tenth, tenth |
| 11 | 11th | eleventh, eleventh |
| 12 | 12th | twelfth, twelfth |
| 13 | 13th | thirteenth, thirteenth |
| 14 | 14th | fourteenth, fourteenth |
| 15 | 15° | fifteenth, fifteenth |
| 16 | 16th | sixteenth, sixteenth |
| 17 | 17th | seventeenth, seventeenth |
| 18 | 18th | eighteenth, eighteenth |
| 19 | 19th | nineteenth, nineteenth |
| 20 | 20° | twentieth, twentieth |
| 21 | 21° | twenty-first, twenty-first |
| 22 | 22° | twenty-second, twenty-second |
| 23 | 23 | twenty-third, twenty-third |
| 24 | 24° | twenty-fourth, twenty-fourth |
| 25 | 25° | twenty-fifth, twenty-fifth |
| 26 | 26° | twenty-sixth, twenty-sixth |
| 27 | 27° | twenty-seventh, twenty-seventh |
| 28 | 28° | twenty-eighth, twenty-eighth |
| 29 | 29° | twenty-ninth, twenty-ninth |
| 30 | 30° | thirtieth, thirtieth |
| 40 | 40° | fortieth, fortieth |
| 50 | 50° | fiftieth, fiftieth |
| 60 | 60° | sixtieth, sixtieth |
| 70 | 70° | seventieth, seventieth |
| 80 | 80° | eightieth, eightieth |
| 90 | 90° | ninetieth, ninetieth |
| 100 | 100° | hundredth, hundredth |
| 200 | 200° | two hundredth, two hundredth |
| 300 | 300° | thirtieth, three hundredth |
| 400 | 400° | fortieth, fortieth |
| 500 | 500° | fiftieth, fiftieth |
| 600 | 600° | sixtieth, sixtieth |
| 700 | 700° | seventieth, seventieth |
| 800 | 800° | eightiethieth, eightiethtieth |
| 900 | 900° | nine hundredth, nine hundredth |
| 1000 | 1000° | thousandth, thousandth |
Continue with: Roman numerals
References
- “Ordinal number” in Wikipedia.
- “Ordinals” in the Pan-Hispanic Dictionary of Doubts of the Royal Spanish Academy.
- “Cardinal and ordinal numbers” in GCF Global.
