common
factor 
An integer that will divide exactly (meaning there is no remainder)
into two or more integers. Commonly used in simplifying fractions. 
composite
number 
Any number that has more than itself and one as factors, i.e.,
is not a prime number. 
denominator 
Any number b, except for zero, in a fraction written in
the form a/b. 
equivalent
fractions 
Fractions which have the same value. 
factor
tree 
A visual representation used to show the prime factors of a number. 
fraction 
Representation of the quotient of two numbers, a and b,
written in the form a/b where b
¹ 0 (b is not equal to zero). 
fraction
bar 
The line in a fraction that separates the numerator and denominator. 
greatest
common factor (GCF) 
The largest integer factor that two or more numbers have in common.
The GCF is most often used to simplify fractions. 
integer 
Any whole number or zero. 
least
common denominator (LCD) 
The least common multiple of the denominators of a group of fractions. 
multiple 
The result of multiplying a number by a whole number. For example,
40 is a multiple of 5, given 5 x 8 = 40. 
multiplier 
An integer multiplied with both the numerator and denominator
of a fraction. 
numerator 
Any integer a, in a fraction written in the form a/b. 
percent 
Symbol is "%", which means, "per one hundred." 
prime
factor 
Prime numbers that are factors of an integer. 
prime
factorization 
An expansion of a product of primes, used to find common factors
and to help simplify fractions. 
prime
number 
A number that has only two factors, 1 and itself. 
proportion 
An equation that states equality between two ratios. 
ratio 
The comparison of two numbers by division. 
reciprocal 
The multiplicative inverse of a given quatity. It is formed by
dividing 1 by the given quantity. To find the reciprocal of a
fraction, simply "flip it over." 
rounding
down 
Done when restricting a decimal to a limited number of places.
When rounding down, we leave the decimal in the place where we
are rounding to as it is given, and discard all digits to its
right. This is done when the next place value is four or less. 
rounding
up 
Done when restricting a decimal to a limited number of places.
When rounding up, we increase the decimal in the place where
we are rounding to by a value of 1, and drop off the digits to
the right. This is done when the next place value is greater
than or equal to five. 
simplified
fraction 
A fraction which has had all common factors of the numerator
and denominator canceled. 
inequality
symbols: 


greater than or equal to 

less than or equal to 

greater than 

less than 