Grade-1 Math – Ordinal Numbers Worksheet

Ordinal Numbers

Ordinal numbers are used to indicate the position of objects relative to others.

Examples:

⇒⇒ Our school is the first in the city.

⇒⇒ My parents are celebrating their tenth anniversary. 

⇒⇒ History books are on the second shelf from the top.

How to Write Ordinal Numbers

Ordinal numbers have letters on them, just like an exponential number. These letters are the last two letters of the ordinal number. 

1st → First 

2nd → Second 

3rd → Third

The ones coming after the first three ordinal numbers are a little easier to learn and write. We add -th to the numbers following the first three ordinal numbers. But, there are some exceptions:

Examples:

⇒⇒ Five → Fifth

⇒⇒ Twelve → Twelfth

∗  Another ordinal number we should pay attention to is the eight. Since eight already ends with the letter -t, we get the eighth number by adding -h without adding -t again.

⇒⇒ Eight → Eighth

∗  When we want to get ‘ninth’,  we drop the -e at the end of the nine and add -th.

⇒⇒ Nine → Ninth

∗  In numbers ending with the letter -y, -y is dropped and -ieth is added to convert it to an ordinal number. We can see this in number 20 and subsequent tens.

⇒⇒ Twenty → Twentieth

⇒⇒ Thirty → Thirtieth

The digits between the tens are expressed as the cardinal number in the first part and the ordinal number in the second part. 

⇒⇒ 21st →  Twenty-first

⇒⇒ 32nd → Thirty-second