Well, you wouldn't exactly say that numbers have genders. In their pure form you would simply say "το" + number. You wouldn't ever say "η/ο δυο, η/ο τρια" .... The reason they use gender endings (like for example in French) is in order to go along with the noun. For example if you wanted to say "she is the second and he is the third " , then you'd use genders saying " Αυτή είναι η δεύτερη και αυτός είναι ο τρίτος".

Exactly! Remember that these also change according to case, so when you're talking about age it'll be in the genitive. Keep up the studying! You seem to be working hard!

11 doesn't change. It remains έντεκα.

Exactly! Remember that these also change according to case, so when you're talking about age it'll be in the genitive. Keep up the studying! You seem to be working hard!