We counted to 10 in ASL, now let's learn some bigger numbers!
To make the number 12-15 in ASL, you do the same hand shapes you did for 1-5, but your hand is turned around so your palm is facing you, and you move your fingers by bending them a little.
11 - Palm facing you, index finger pointing up, then bend your finger once or twice.
12 - Palm facing you, index and tall finger pointing up, then bend your fingers once or twice.
13 - Palm facing you, index and tall fingers pointing up and thumb out, then bend your index and tall fingers once or twice.
14 - Palm facing you, thumb held in and the other 4 fingers pointing up, bend your fingers once or twice.
15 - Palm facing you, open hand all fingers up, then bend your fingers once or twice, but not your thumb.
Here is a helpful video to show how these signs are done.
ASL Numbers 11-20 in Sign Language | Learn how to Sign Numbers

(from: wikipedia - american sign language)
Italian: undici, dodici, tredici, quattordici, quindici
German: elf, zwölf, dreizehn, vierzehn, fünfzehn
Spanish: once, doce, trese, catorce, quince
French: onze, douze, treize, quatorze, quinze