The term "3x5" typically refers to a mathematical expression representing the multiplication of the numbers 3 and 5. When calculated, 3 multiplied by 5 equals 15. This expression is often used in basic arithmetic and can be found in various educational settings to teach multiplication concepts. In a different context, "3x5" can also refer to a common size for index cards, which measure 3 inches by 5 inches. These cards are frequently used for note-taking, organizing information, or studying, making them a popular tool among students and professionals alike.