Ordinal numbers   (บอกลําดับ)

1st - the first 21st - the twenty-first

2nd - the second 22nd - the twenty-second

3rd - the third 23rd - the twenty-third

4th - the forth 24th - the twenty-fourth

5th - the fifth 25th - the twenty-fifth

6th - the sixth 26th - the twenty-sixth

7th - the seventh 27th - the twenty-seventh

8th - the eighth 28th - the twenty-eighth

9th - the ninth 29th - the twenty-ninth

10th - the tenth 30th - the thirtieth

11th - the eleventh 40th - the fortieth

12th - the twelfth 50th - the fiftieth

13th - the thirteenth 60th - the sixtieth

14th - the fourteenth 70th - the seventieth

15th - the fifteenth 80th - the eightieth

16th - the sixteenth 90th - the ninetieth

17th - the seventeenth 100th - the one hundredth

18th - the eighteenth 200th - the two hundredth

19th - the nineteenth 300th - the three hundredth

20th - the twentieth 400th - the four hundredth