Expression used to ask someone's age (e.g., "How old are you?"). Casual; the polite form is "oikutsu."
お子さんは何歳ですか？
How old is your child?
彼は何歳で大学に入ったの？
How old was he when he entered university?
あの人、実際には何歳に見える？
How old does that person actually look?