California Assessment of Student Performance and Progress (CAASPP) Math Practice Exam

A factor of a number is defined as a number that divides the given number evenly, meaning it has to divide that number without leaving a remainder. This is the essential property that determines whether a number is a factor of another. For example, if you take the number 12, its factors include 1, 2, 3, 4, 6, and 12 itself, as all of these numbers can divide 12 exactly, resulting in whole numbers (0 remainders). The other choices do not inherently define a factor. A factor does not need to be a decimal number; it could be an integer, positive or negative. Factors also are not required to be larger than the number they divide; in fact, many factors are smaller. As for being a prime number, while some factors can indeed be prime, it is not a requirement for a number to be classified as a factor. Therefore, the defining characteristic is that a factor must divide another number without leaving a remainder.