We counted to 69 in ASL, let's keep going!
To do the sign for 70, make the hand sign for 7, with your index, middle and pinky fingers up, and holding your ring finger down with your thumb.
Then close your fingers together all pointed forward away from you, for zero.
For 71 through 79, just do the sign for 7, 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: settanta, settantuno, settantadue, settantatre, settantaquattro, settantacinque, settantasei, settantasette, settantotto, settantanove
German: siebzig, einundsiebzig, zweiundsiebzig, dreiundsiebzig, vierundsiebzig, fünfundsiebzig, sechsundsiebzig, siebenundsiebzig, achtundsiebzig, neunundsiebzig
Spanish: setenta, setenta y uno, setenta y dos, setenta y tres, setenta y cuatro, setenta y cinco, setenta y seis, setenta y siete, setenta y ocho, setenta y nueve
French: soixante-dix, soixante et onze, soixante-douze, soixante-treize, soixante-quatorze, soixante-quinze, soixante-seize, soixante dix sept, soixante dix huit, soixante dix neuf