Final answer:
Keira's former buyer client's belief in numerology affected their house hunting preferences.
Step-by-step explanation:
Numerology is the belief in a mystical relationship between numbers and events. In this case, Keira's former buyer client believed that houses with addresses that add up to three were preferable. Numerology is not a concept in mathematics but rather a belief system related to metaphysics. Therefore, this question is not about mathematics but rather about a personal belief.