1 first
2 second
3 third
4 fourth
5 fifth
6 sixth
7 seventh
8 eighth
9 ninth
10 tenth
11 eleventh
12 twelfth
13 thirteenth
14 fourteenth
15 fifteenth
16 sixteenth
17 seventeenth
18 eighteenth
19 nineteenth
20 twentieth
30 thirtieth
40 fortieth
50 fiftieth
60 sixtieth
70 seventieth
80 eightieth
90 ninetieth