Find the GCF 20 , 27

$20$ , $27$

Find the common factors for the numerical part:

$20, 27$

The factors for $20$ are $1, 2, 4, 5, 10, 20$ .

The factors for $20$ are all numbers between $1$ and $20$ , which divide $20$ evenly.

Check numbers between $1$ and $20$

Find the factor pairs of $20$ where $x \cdot y = 20$ .

$\begin{array}{c} x & y \\ 1 & 20 \\ 2 & 10 \\ 4 & 5 \end{array}$

List the factors for $20$ .

$1, 2, 4, 5, 10, 20$

The factors for $27$ are $1, 3, 9, 27$ .

The factors for $27$ are all numbers between $1$ and $27$ , which divide $27$ evenly.

Check numbers between $1$ and $27$

Find the factor pairs of $27$ where $x \cdot y = 27$ .

$\begin{array}{c} x & y \\ 1 & 27 \\ 3 & 9 \end{array}$

List the factors for $27$ .

$1, 3, 9, 27$

List all the factors for $20, 27$ to find the common factors.

$20$ : $1, 2, 4, 5, 10, 20$

$27$ : $1, 3, 9, 27$

The common factors for $20, 27$ are $1$ .

$1$

The GCF (HCF) of the numerical factors $1$ is $1$ .

$1$