Find the GCF 30 , 40

$30$ , $40$

Find the common factors for the numerical part:

$30, 40$

The factors for $30$ are $1, 2, 3, 5, 6, 10, 15, 30$ .

The factors for $30$ are all numbers between $1$ and $30$ , which divide $30$ evenly.

Check numbers between $1$ and $30$

Find the factor pairs of $30$ where $x \cdot y = 30$ .

$\begin{array}{c} x & y \\ 1 & 30 \\ 2 & 15 \\ 3 & 10 \\ 5 & 6 \end{array}$

List the factors for $30$ .

$1, 2, 3, 5, 6, 10, 15, 30$

The factors for $40$ are $1, 2, 4, 5, 8, 10, 20, 40$ .

The factors for $40$ are all numbers between $1$ and $40$ , which divide $40$ evenly.

Check numbers between $1$ and $40$

Find the factor pairs of $40$ where $x \cdot y = 40$ .

$\begin{array}{c} x & y \\ 1 & 40 \\ 2 & 20 \\ 4 & 10 \\ 5 & 8 \end{array}$

List the factors for $40$ .

$1, 2, 4, 5, 8, 10, 20, 40$

List all the factors for $30, 40$ to find the common factors.

$30$ : $1, 2, 3, 5, 6, 10, 15, 30$

$40$ : $1, 2, 4, 5, 8, 10, 20, 40$

The common factors for $30, 40$ are $1, 2, 5, 10$ .

$1, 2, 5, 10$

The GCF (HCF) of the numerical factors $1, 2, 5, 10$ is $10$ .

$10$