any nonzero number that is a mulitple of the denominators of two or more fractions [ ex: the fractions 1/2 and 2/3 have common denominators 6, 12, 18, and so on
common factor
a number that is a factorof two or more given numbers
denominator
the bottom number in a fraction which tells the number of peices making up a whole
factor tree
a digram used to show the prime factors of a number
fraction
a number showing a part of a whole
numerator
the top number in a fraction which tells the number of parts selected
