Guess the Age! Meet my chicks!!

[zhutson789]

Meet my five babies! 3 Rhode Island Reds and 2 Ameraucanas, all pullets (or should be) I got them from a local store on Sunday, please help me guess their age so I can take care of them the best I can! (treats, temp, etc.) Each picture is a different chicken. Thank you so much!!!!

7-10 days old. Americanas have a 80% chance if I remember. Hopefully hens!