We counted to 29 in ASL, let's keep going!
To do the sign for 30, make the hand sign for 3 with your thumb index and middle finger extended, palm facing away. Then close your fingers together all pointed forward away from you, for zero.
For 31 through 39, just do the sign for 3, and then the sign for the number 1-9.
Here is a helpful video to show how these signs are done.
ASL Numbers 30-100 in Sign Language - My Smart Hands
(from: wikipedia - american sign language)
Italian: Trenta, trentuno, trentadue, trentatré, trentaquattro, trentacinque, trentasei, trentasette, trentotto, trentanove
German: einunddreißig, zweiunddreißig, dreiunddreißig, vierunddreißig, fünfunddreißig, sechsunddreißig, siebenunddreißig, achtunddreißig, neununddreißig
Spanish: treinta y uno, treinta y dos, treinta y tres, treinta y cuatro, treinta y cinco, treinta y seis, treinta y siete, treinta y ocho, treinta y nueve
French: trente et un, trente-deux, trente-trois, trente-quatre, trente-cinq, trente-six, trente-sept, trente-huit, trente-neuf