Which term refers to the largest number that divides each number in a given set evenly?

• A. GCF
• B. LCM
• C. Composite number
• D. Front-end estimation

Answer: (A)

The largest number that divides every number in a given set evenly is the greatest common factor, or GCF. This number must be a divisor of each member of the set, and among all possible common divisors, it is the biggest. You can find it by factoring each number and looking for the prime factors that appear in all of them, using the smallest exponent for each shared factor. Or you can list the factors of each number and identify the largest one that appears in every list. This concept specifically captures the idea of a common divisor that is as large as possible.

For contrast, the least common multiple is about multiples that all the numbers share, not about common divisors. A composite number is simply a number with more than two factors, and front-end estimation is a quick rounding method for approximate mental math, not about divisibility.