• The smallest prime number : Two
  • A room with this number of people has a 50% chance of two of them having the same birthday : Twentythree
  • This number cannot be represented by Roman numerals : Zero
  • The number of lives that a cat is said to have : Nine
  • In blackjack, the goal is to get this number : Twentyone
  • Single-digit number that is considered lucky : Seven
  • Most months have this many days : Thirtyone
  • It’s usually the number of items on “top” or “most” lists : Ten