My children can answer it in a number of ways. Older one, depending on the mood, can just think and calculate, can say “I don’t care”, outright ignore the question, answer with a joke (“bazillion”).
Younger one cannot calculate yet, and will cheerfully answer with a random number, or a string of numbers — 15! 20! 45! 18!
These LLMs fit into “human-like” behavior no problem. It just doesn’t always behave like the smartest and self-aware person on the planet.