A factor divides a number with no remainder. A multiple is a product of a number and an integer. A prime number greater than 1 has exactly two positive factors: 1 and itself.
Common divisibility rules: even numbers are divisible by 2; a digit sum divisible by 3 means the number is divisible by 3; numbers ending in 0 or 5 are divisible by 5.
The greatest common factor (GCF) is the largest factor shared by the numbers. The least common multiple (LCM) is the smallest positive multiple they share.
For 24 and 36, the shared factors include 1, 2, 3, 4, 6, and 12, so the GCF is 12.
For 4 and 6, multiples first meet at 12, so the LCM is 12.
Saves your progress and schedules spaced review of anything you miss.
Unlock the full practice bank + timed full-length exam simulation +
practice across topics to help you prepare for the exam.
The lesson quiz is included with a free account.
$0 today — card required to start your trial. Cancel anytime before day 3.