# Reducing Fractions (Simplest Form)

A fraction is in
**
simplest form
**
if the
greatest common factor
(GCF) of its
numerator
and
denominator
is
$1$
-- that is, if they share no common factors other than
$1$
.

For example,

$\frac{3}{11}$

is in simplest form, since $3\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{and}\text{\hspace{0.17em}}\text{\hspace{0.17em}}11$ have no common factors other than $1$ . However,

$\frac{6}{21}$

is not in simplest form, since $6\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{and}\text{\hspace{0.17em}}\text{\hspace{0.17em}}21$ share a common factor of $3$ .

To reduce a fraction, divide both the numerator and denominator by the GCF. (This is also known as "writing a fraction in lowest terms".)

This is sometimes shown as "canceling" the common factors.

$\frac{6}{21}=\frac{\overline{)3}\cdot 2}{\overline{)3}\cdot 7}=\frac{2}{7}$

Note that the result is an equivalent fraction in simplest form.